[MUSIC] Two very different discoveries have given new insight into the decline and fall of the Roman Empire. These cargo ships were found in the mud of an ancient harbor, they once sailed the imperial trade routes. [MUSIC] But with the ships came disease and with the disease, death. [MUSIC] Inside a strange pottery coffin, the skeleton of a tiny baby, is revealed what sort of death it might have been. With the help of forensic science, the bones are telling a remarkable story, the story of a pestilence that swept through the Roman world. [MUSIC] The Romans created a huge and sophisticated empire, far more advanced than anything else of its time. And perhaps the most powerful symbol of that great empire is the Colosseum. Back then with its spectacular gladiatorial battles, it must have been one of the wonders of the ancient world. [MUSIC] The power of the Roman Empire lasted for nearly five centuries and eventually came to an end between 400 and 500 AD. But the fall didn't happen overnight, the empire had been in decline for years. [MUSIC] There are many theories as to what finished Rome off, everything from lead poisoning to disastrous shortages of food. [MUSIC] It was almost certainly a combination of factors, but whatever the causes, the empire soon fell to barbarian tribes. [MUSIC] Rome was ransacked, and the anarchy of the Dark Ages began. [MUSIC] [NOISE] Evidence of these violent times has rarely been found. But recently, on the island of Sardinia, close to Italy, a fascinating discovery has emerged. 2000 years ago, Olbia was a thriving Roman port. [NOISE] Today, a new motorway is being built along the waterfront. [NOISE] Much to the annoyance of the road planners, they came across the old harbor and it was full of Roman ships. Archaeologists are now frantically excavating, in a race with the bulldozers. >> [FOREIGN] >> Eduardo Ricciardi, an expert on ancient ships, was brought in to supervise the dig. Once the wood is exposed, it must be kept wet, or it will rapidly decay. From the sturdy structure of the boats and their size, some over 30 meters long, it soon became clear that they were cargo ships. >> This is massive, Eduardo, what is this chunk of timber? >> This is the joint between the keel, which is here, and this is the stand post. >> I mean, is this what distinguishes a cargo ship from a war ship, just the sheer size of the timbers that are used? >> Yes, normally a warship is long and narrow and here we have a boat very wide. >> And very solidly built. >> Very solid. [MUSIC] >> In total, Eduardo and his team excavated 16 Roman ships. Never before have so many been found in one place and so well preserved. Even the wooden planking was still intact. [MUSIC] It was a unique find. >> We began to believe that it was a fleet. After starting the few elements of construction, we saw that the boats were of the same age. So it is easy to think that they sank together, now we are sure. >> Because the ships were all so neatly lined up against the harbor wall it was unlikely that a storm had destroyed them. Eduardo thought it was probably war and finding out in which year the ships sank might reveal the enemy. Essential to the dating was pottery and coin expert, Giovanna Pietra. >> [FOREIGN] >> [FOREIGN] >> So this is a coin from the Emperor Theodore. >> [FOREIGN] >> They were all in circulation in the fifth century [FOREIGN] after Christ. >> Right, so that's the date when you think that the ships were sunk here? >> [FOREIGN] >> So they can use both the coins and the samples of ceramics. >> Because you can date the pots very closely, can you? >> [FOREIGN] >> So with the pots they can date some of them almost to the year. Really? >> Yeah. >> The time around 450 AD, when they believe the cargo boat sank, is of great significance to Rome. Historical records describe how during this period an infamous barbarian tribe, the Vandals invaded Sardinia. >> This is a war attack from Vandals coming from North Africa, immediately before the fall of Rome, destroying important Roman towns, one of them is Olbia. And I believe that this fleet is the one destroyed by Vandals. >> What we don't know is, why at this time, the Roman military became so vulnerable to attacks by barbarians. But a new theory has just been suggested that might help to explain why the Romans became so weak. And the key to this theory comes from another archaeological site, back on mainland Italy, near a small and beautiful hill town called Lignano. [MUSIC] Today, Lignano is perched on a hill, but back in Roman times the settlement was lower down valley, close to the river Tiber. Then, the Tiber was Lignano's most important transport link to Rome, just 70 kilometers to the south. [MUSIC] David Soren is an expert on Roman archaeology. [MUSIC] He's the architect of the new theory and it's based on just one excavation close to the town. [MUSIC] David is convinced that he's uncovered the role of disease in the fall of Rome. [MUSIC] A Roman villa was discovered accidentally when a farmer came across some ancient pottery in his field. >> [FOREIGN] >> [FOREIGN] >> The local Italian archaeologists knew of David Soren's reputation. And invited him to help with the dig. >> See what this wall actually looked like. There's a good piece, and that's got red paint on it. I thought it looked like a site with some possibilities, but it didn't seem to be as exciting as many other sites around the Mediterranean that I had looked at. I had no idea what we were going to find. >> At first there didn't seem to be any exceptional about the villa. But as they set to work, it became apparent that the buildings, with their many rooms, covered a very large area. So far, only a quarter has been excavated. >> Probably was about the size, of what in America we would say, is a good size shopping mall. >> That's pretty substantial then, pretty big. >> For the wealthy part of it, for the part that the Dominos, the Lord of it would live in, has these beautiful mosaics that were put down and if we come down here we can actually even see a few of these. [MUSIC] >> So this whole room has got mosaic floor, has it? >> Yes, you can see the little rosettes here and a simple border. And this is a style we would find typically at the end of the 1st century BC. The size of the cubes and the design, it's fairly simple and black and white. [MUSIC] >> The mosaics were found in the two living rooms at the front of the villa. Once these have been excavated, David decided to explore the store rooms to the side of the villa. He assumed they be much plainer than the more decorative living quarters. [MUSIC] But here was something even more remarkable. >> One morning we were starting the excavation of the store room. It didn't look like that was going to be a very interesting week to be starting with that. And almost immediately as I was coming down from the surface, we hit what looked like a human burial, a burial of a baby. [NOISE] Right next to that, we found another baby, [NOISE] within a few hours we found another baby. [NOISE] We ended up that day with seven. [NOISE] That was the first moment when I realized something pretty strange was going on here. >> David was determined to find out how they died. He contacted a colleague at his university in Arizona, Walter Birkby, a forensic anthropologist, began by estimating the age of the children when they died.ir >> One of the easiest ways to do this, is to take a long bone, such as a femur, an immature femur, you can measure the maximum length. And the maximum length is 179 millimeters, or 17.9 centimeters and it would fall between 2 years and 3 years. When we’re dealing with immature material, we can also use a skull, such as this late fetus that we have here. And those measurements would be, the length of this wedge-shaped bone here, in the skull and know how old that person might have been. >> Of the 47 children buried in the villa, Walter Birkby discovered that nearly half were babies that were premature or stillborn. The oldest child was just three years old. >> Finding all of these kids, fetal as well as very young, I think that makes it more of a different kind of a situation then ones usually accustomed to in dealing with New World and or possibly Old World archeology. [MUSIC] >> Some of the babies were buried inside what were effectively pottery coffins. They smashed open one of these distinctive storage jars that were used for wine or oil, and then carefully reassembled it around the body of a tiny child. The storage jar protected all the fragile bones like the plates of the skull, and this also meant that a lot of the tiny bones which might otherwise have got lost have all been found, even the little tiny bones of the fingers. [MUSIC] They've been able to tell when these children died, from the pots that they were buried in. They can be dated to around 450 AD from the clay that they're made from, and also from their very distinctive shape. [NOISE] [MUSIC] >> In it's heyday, at the end of the First Century BC, the villa must of been a splendid dwelling. But David Soren has evidence that it gradually fell into disrepair. And around 450 A.D., the villa for some reason, had become the site of a cemetery. >> It wasn't built on particularly stable ground. It was built more on soil than on a solid area, and you're gonna have some major structural damage. >> By the middle of the 5th century AD, the villa was a crumbling ruin, with collapsing walls and cracked mosaic floors. [MUSIC] It was in this place of decay, that the children were laid to rest. [MUSIC] >> Unlike today, ancient Romans very rarely buried their babies in cemeteries. They didn't believe that very young children should be mourned, or even given a formal burial. Their bodies were normally just disposed of with very little care or ceremony. [SOUND] >> People do not bring offerings to those children who die in infancy. Our laws forbid us to mourn for infants. >> It's always hard, when you lose a child, but, you know, times were tough, this was not the 21st century. Medicine was primitive at best, so the women just kept shucking out kids because that’s what you did. You had to have progeny, for whatever reason. But there’s always grief over the loss of one child, I’m sure. >> [FOREIGN] >> Then, unexpectedly, more bodies were found at the villa. [NOISE] [MUSIC] The most surprising thing to me was that in among the baby's were animal bones and particularly the bones of dogs. And we had to bring in a special forensic expert to deal with these animals. They turned out to be puppies, almost every one and they were all five to six months in age. The puppies had been, in one case, severed in half, cut in half. And in almost all the other cases, beheaded. And not just beheaded by being cut, but they seem to have been perhaps killed and then had their jaws just ripped apart, ripped open. It was very hard to match the heads to the the bodies of these animals. So there was some kind of ritual going on here. At this late stage of the empire, performing pagan rituals was illegal and punishable by death. By 450 A.D., the Roman emperor, and most of his subjects, and converted to Christianity. But in rural areas, many people still continued to worship their pagan gods. Many of them also still believed in witchcraft and black magic. In times of trouble, would revert to their old practices. Here at the villa, this included the sacrifice of animals, like the puppies. They were decapitated as offerings to the Gods. In the hope of purifying the area and warding off evil. Other animals had been sacrificed. One child was found with a skeleton of a frog, considered by many sorcerers to be a cure for fevers. David believed that these outlawed rituals were a sign of the villagers fear. [SOUND] Nowhere was this more evident than in the burial of the three-year-old child. >> It was as if people were really afraid of this one, the arms seemed to have been weighted down with stones, one on each. And then the feet had a big tile, and when you looked at it it was quite eerie. We know that the Romans were afraid of spirits that rose up from the dead and wandered the earth and it seemed like this It was very important to keep this child down. And I think that gives you some sense of the fear of the community. >> In Roman times the villages had harnessed black magic to deal with the deaths of their children. 1500 years later David Sorem was using archaeological science to find out what had really happened. Had all the deaths occurred at the same time, or over many years? He noticed that the skeletons, although buried at different depths, were all part of the same soil layer. We would find pottery at the bottom which would join to the top, and we got things, a piece here, and part of this was found up at the top, part of it at the bottom, but they actually do fit together. >> And despite the fact that this has got lots of bits of tile and stone in it. You're right, there's no obvious layers are there? Where one lots gone in and then another lots gone in it. And it all looks like it's just one huge deposit. >> Yes, I think that's exactly it. And we were finding ash also scattered all through it. So, I think it's pretty clearly all put there at once. >> So, were the baby burials distributed uniformly throughout this whole layer? >> No, that's a critical point. We would find perhaps one at the bottom in a very wide area. Then as you got closer to the top, we were finding in this room as many as seven burials together. We had something that was escalating. And that was the one thing that struck me immediately, that we had an epidemic. >> David thought the epidemic might have been malaria. Until as recently as the late 1940's malaria was a big killer in Italy, especially around the low lying swampy areas of the river Tiber. Also, Roman writers had described a disease which sounded very much like malaria. In 467 A.D., a traveler close to Linarno was struck down with just such an illness. [MUSIC] My body was suffocated by breathing the air. It was drowning in poisonous gas. And alternated between sweats and chills. Meanwhile, fever and thirst ravaged the deepest recesses of my heart and bones. >> Despite these accounts from the Roman period, no archaeologist has yet found direct evidence of malaria at this time. But David was convinced that it was malaria that had killed the children of Linano, and set out to prove it. He enlisted the help of a number of experts. >> The thing that we were looking at were some pathologies that were starting to appear on the bones, and this was interesting because it gives us a handle maybe on the cause of death. A cross section of a normal bone reveals solid walls, but this bone from the baby cemetery has honeycomb walls, and the eye sockets of the skull were heavily pitted. >> All these are signs of serious blood disorders such as anemia, but anemia wasn't the only candidate. >> Other than the usual run of anemia's that you're thinking of, malaria had to be one of our considerations in that type of analyses. Now David through the literature search, they're starting to come up with, for that particular time period, things that bespeak a good possibility. Still a possibility. Not definitive, a possibility that this was malaria. There was a another small piece of evidence among the bones of the children. Traces of plant ash. Karen Adams was the botanist who investigated the burnt remains. And she started by taking samples of modern plants. I went to the Roman age Villi, collected all the trees. There were oaks. There were pines. Then there were other shrubby things and various plant families. I burned all the wood and had a really good chance, then, of identifying the material that came out of the Roman age villa. She compared the microscopic structure of the ancient wood with that of the modern samples. Eventually, she found a perfect match. The burnt plant was honeysuckle. >> The honeysuckle is significant because, in the first place, it wouldn't have been >> A routinely utilized wood at Luyano. It's a shrub and it doesn't have very big wood. It's important because it has medicinal properties. >> The Roman writer, Pliny had noted that honeysuckle was used as a cure for an enlarged spleen, a classic symptom of malaria. >> Finding a little pile of burned honeysuckle in association with the burial, suggests that perhaps they at one point tried to treat this infant, with honeysuckle and it might not have worked, or that simply honeysuckle was being burned as part of the burial ritual. [MUSIC] I had all this circumstantial evidence ranging from the honeysuckle to the black magic that was being practiced to the proximity of the Tibur. And everyone I talked to said, well you know it sounds to us like malaria. Malaria is spread by the bite of a mosquito. Essentially, they're like flying hypodermic syringes passing infection from person to person. But the male mosquito is entirely harmless. It's the female that bites and passes on the disease. In the salivary glands of the malarial mosquito is a tiny creature the malarial parasite itself As the female mosquito sucks the blood of her victim, the parasite is released along with the saliva and infects the new victim. Fortunately, these particular mosquitos aren't carrying malaria, or so I'm told. >> As a world expert on mosquitoes, Mario Kalutsi is fascinated to know how and when they spread malaria across the Roman Empire. To study them today, he collects mosquito larvae from the swamps near Lanyano. An ideal breeding ground. In the lab, the different species can be identified. Although the particular mosquitoes which carry malaria have been eradicated from most of the developed world, in many tropical countries they remain a devastating killer. In Africa, every year, they kill two million people. This type, the Anopheles mosquito, is the deadliest insect on Earth. >> This is responsible for 3,000 children dying each day in Africa. And this mosquito is responsible of 90% of these deaths, 90% of malaria cases. Don't you hate mosquitoes for what they do? >> Well I think that the more we know about these mosquitoes, these terrific mosquitoes, and more we able to control it. [SOUND] >> After the malaria parasites have entered their human host they eventually attack the red cells in the blood. These are red blood cells infected by the parasite, the small blue crescent. In the process, the blood cells are destroyed and begin to clog up vital organs including the brain. There are four different strains of malaria that infect humans, but one attacks many more blood cells and is therefore much more deadly. It's called falciparum. Mario Coluzzi's research has helped confirm that falciparum malaria originated in Central Africa and spread northwards. But, at some point, the advance of the disease was halted. The Mediterranean Sea blocked the way. Mario was trying to figure out how this particularly serious form of malaria had managed to get into Italy. And it must have started at some point, and yet it didn't seem to have been here in early antiquity. And his question is, his idea was to figure out when it came. >> Mosquitoes can only fly about 100 meters. So they could never have made the crossing from Africa to Italy on their own. So how did this disease travel? Well, sailors or slaves onboard a ship might have been infected with the parasite without showing any signs of disease. Or their water supply could have been contaminated with mosquito larvae. But however the disease traveled, it wasn’t very long before this new and deadly strain of malaria had crossed the Mediterranean. [SOUND] Slowly but surely, falciparum malaria was moving north. It seems the island of Sardinia was hit by the disease before it reached mainland Italy. >> Ironically, the very success of the empire was helping to spread the disease that might eventually contribute to its downfall. Roman writers described Sardinia as a hot bed of disease, most probably Malaria. >> The island is unhealthy in summer, especially the fertile regions. The generals know it is not profitable to maintain a military presence in these areas. Essential to the spread of malaria were ships, such as those found in the harbor of Albia. [SOUND] Could these folks have been involved in the trade from North Africa to south India, and then on to Rome? Yes, maybe. It's easier that they were doing the trade. >> It is. >> Grains from here to Rome and from other things here. We are finding many nice things coming from Rome. A glass drinking vessel and a necklace, almost certainly came from Rome but some of the more everyday pottery confirmed the trade links with Africa. >> This is [FOREIGN]. >> These are from North Africa from Tunisia. >> All of these. So these would have been transported across from Africa in ships to the port here at Albia?. >> [FOREIGN] >> Sardinia was a stepping stone for malaria. By ship Rome was a short two day journey away, and Mario Kalutsi believes that this active trade was how both mosquito and disease eventually reached mainland Italy. [SOUND] But at first they found it difficult to cope with the cooler climate. To survive the mosquitoes have to change their habits. They evolved to live indoors and places such as cow sheds. Where Maria's team can still find mosquitoes. [SOUND] Actually, they're hanging all over the ceiling there. >> Yes, they probably feed during the night on the couples. And now, they're digesting the blood meal. >> Right. So, why's this such a good place for mosquitoes? >> There's several reasons. First of all, outdoor is TTe temperature is too low for them to survive. And then, here, they find also the cows. So, they have everything. >> Plenty of blood for them. >> Yes, yes. >> In Roman times you've got people living quite close by. >> Of course, of course. >> They would end up >> Have you? >> And that's the most important in temperate areas like Italy, where the temperature is not so good for the mosquitoes not for the parasite. So the fact that they were in the environments available is very important for America's future. >> So this why you come to cow shed to look for mosquitoes today. >> Yeah, yeah. >> Have a look. >> [FOREIGN] >> that's quite a collection, isn't it? >> There was no stopping the newly adapted mosquito. In the south of Italy, some thriving coastal towns were abandoned altogether. Until very recently, these areas have been uninhabitable because of malaria, and Mario is convinced that is was falciparum malaria arriving during Roman times that first led to their abandonment. Mario's research dovetailed nicely with David Soren's own theory about the epidemic at Linyano. Even so, many American archaeologists remained unconvinced that the children had died of malaria. They argued that Soren's evidence was only circumstantial, and that there was really nothing that unusual about the cemetery. Well, the main criticism of my work was that people kept saying this was an ordinary cemetery, and the cemetery, they said, was put in over a very long period of time. And each one of these burials represented a normal burial. And I kept hearing that over and over again, normal burial. >> David needed new and stronger evidence if he was to ever confirm his theory. His main problem was having to rely on children's skeletons. Adults would be much more likely to provide the proof of malaria. [NOISE] No adult burials have been found in the area and without this supporting evidence, the attacks on his theory continued. [MUSIC] >> If you come up with new theories People want to take a shot at you, just try to find a way to cut you down to size. That's what I experienced and it wasn't very pleasant. [MUSIC] But I felt that I was right and so it didn't really matter what people were saying, as long as in the long run there might be some way of being proven correct. >> It was then that David heard about a new technique, which was to change everything. I got some emails from different people who were suggesting that there was this new field of DNA analysis and if I actually would take some of my bones, get permission and have them tested. And it might just be possible, although it hadn't been done before, that we could figure out if this malaria really existed. [SOUND] >> Robert Sellers is a DNA expert based in Manchester. He's developed new techniques for identifying diseases from their DNA. And was on the lookout for test cases where there was a probable connection between a burial and a specific disease. He found a research paper by David that mentioned a plan to test the Lugnano bones for malarial DNA. But the article was already three years old. >> I assumed that the workers were doing progress somewhere in the states, but I was curious about it so I sent him an email to ask him what sorts of results he was getting. >> Everybody in America that I asked to analyze the bones refused me and said my theories were not very practical. >> They must have been extremely pleased to get your email I'd imagine. >> I think so, yes. So, it's a surprise to me as well, getting the bones. I didn't expect to receive any. >> I just couldn't get them to him fast enough. >> These bones seem in remarkable good condition for children of this age. They're very well preserved, and yet they're so tiny, and fragile, and the thinness of the cranium skull is. Malarial DNA was unlikely to have survived in the skeletons of premature infants. So Robert Solaris specifically asked David for bones from the older children. David was concerned. >> I said, well I've got these premature infants. I've got neonates aborted fetuses. I only have really one old older child for you, but I was very worried that with these younger ones, that there wouldn't be any chance to find anything and even with the older one too. [MUSIC] >> Robert and his research team faced a herculean task, not only does DNA degrade overtime but also, much of what was present in the bones would be the human DNA of a child. [MUSIC] They were searching for genetic evidence of a tiny worm-like parasite. [NOISE] >> Presumed that these bones will be stuffed full of human DNA. >> Yes. >> But a very, very small amount of potentially of the parasite DNA. >> Parasite's can invade up to, in severe cases, up to 70 or 80% of all red blood cells. There can be a lot of parasite here and around as well. >> What if somebody was mildly infected by malaria, it wouldn't give a signature, presumably? >> I wouldn't have thought, no, [INAUDIBLE] thousand years were not available since the [INAUDIBLE], no. >> It must be rather worrying not knowing whether anything's gonna turn up. >> It's an occupational hazard. Receptionist business. I think everyone who works in this field has had experiences of working on action material that has produced nothing. >> Undaunted, Robert's team extracted what little DNA they could from the bones and checked to see whether is was malaria or not. All the first samples they tested gave the same result. No malaria present. >> I was constantly communicating with him. Certainly every two, three months. And it was the syndrome in America which we say, it's Now Coach? Now? Am I going in now? Was that kind of thing. Have you got anything yet? [MUSIC] >> Robert was keeping the best bones to last so that they can perfect their techniques. After all the other samples had been tested, he finally went ahead with the leg bone of the three year old child. [MUSIC] It produced the best preserved DNA they'd found so far, but to know for certain that it was malaria, Robert had to compare with the DNA sequence of the present day disease. >> So this is the sequence, I presume, for malaria itself, is it? >> Yes. This is a small part of the modern DNA sequence. >> All right, and this is the sequence that you managed to extract from the bones from the cemetery. >> Partly, yes. >> Cuz they were both made up of, what is it, four letters, aren't there? >> A,C,G and T. Right. >> And so is it that simple? Do you just have to try and match them up? >> Yes. >> To see if they match and if they do then. >> Yes. [MUSIC] >> You found what you're looking for? >> Yes. >> So in this section. Certainly. >> Yes. >> And this is it isn't it? >> If the degree of divergence between sequences was substantial, then we'd have to conclude that we haven't got malaria. We've got something else. >> But here, you’re positive, are you? >> Yes. >> One day, he wrote me back. And he said yes. I think we really have got not only evidence of malaria, but of the particular kind of malaria you think we have. And at that point, it was like eureka. [SOUND] >> It was concrete evidence of the earliest confirmed case of malaria in history. Robert Solaris was convinced that this one occurrence strongly suggested an epidemic. >> Although we only found malaria in one skeleton, from modern knowledge of the epidemiology of the disease. We can say that it doesn't tend to occur sporadically. If environment or conditions are favorable for it to be present, a lot of people would've had it. >> So, if you got one positive case? >> There would be many infected, yes. >> Malaria is most deadly when it first hits a population. Mario Coluzzi was called in to help with just such an epidemic, on the island of Madagascar. >> When malaria is epidemic, so is coming for the first time or after a period that there was no contact of man with parasites, is very severe. [SOUND] >> By 1986, much of Madagascar had been free of malaria for over 20 years. But then, the disease suddenly returned. [MUSIC] In some valleys up to 40% of the population died. In certain villages, there weren't even enough survivors to bury the dead. >> You see miscarriages and people dying at all ages. So, it's a dramatic response of the population. The population is afraid, and this is generally described as a pestilence of the old time. [MUSIC] This, malaria at it's most severe, must have happened at Lugnano when malaria mosquitoes first arrived. These new epidemics are so deadly because nobody has built up any immunity to the disease. [MUSIC] >> In a population where it's not present continuously, all the time, and that was probably the case in Lugnano, many people might not have had previous experience of it. So, I think it would have had devastating effects. >> So it could actually almost wipe out a generation, couldn't it? >> Yes, it could, yes. >> Robert's work for me just puts this all in a context where I feel I can go back and see the way it was and feel it. Not just dig it, but really feel it and experience it. And when you can get to that point in archaeology, that's really when you're getting somewhere. That's what it's all about. [MUSIC] It's 450 AD. By late summer, over half the people of Lugnano have fallen ill with the mysterious plague. Many of the adults are close to death, but it's the expectant mothers and the very young who are most at risk. The pregnant women lose their unborn babies. The younger children cannot fight of the disease and die. [MUSIC] >> Farms would be abandoned. I think harvests would not be accomplished. As these epidemics would sweep through and so many people would die, people would move to other areas. And it's quite clear from the literature of the fifth century AD, that the Romans could talk about zones of pestilence. [MUSIC] >> Some people have already deserted Lugnana. Those who stay are terrified of both the epidemic and the bodies of the dead. They take their children to the ruined villa for burial. [MUSIC] >> The most productive plains, coastal plains, were abandoned. >> All of these areas, the coastal areas then, these were the most unhealthy. But this is where all the really important, a lot of the really important settlements where. >> Yes, and so these settlement had to move and this was the crisis of the Roman Empire. [MUSIC] >> Although ostensibly Christian, the survivors believed their only salvation lies in pagan rituals. A dead baby is placed in an amphora. [MUSIC] The three year old girl is buried next. They're frightened of her soul rising up and so use stones and a roof tile to weigh down her body. [MUSIC] A frog is placed on another grave. And in an attempt to placate the gods of the underworld, puppies are sacrificed. [MUSIC] Fear has brought about the return of pagan rituals. David Soren believes that similar scenes were being replayed in many parts of Italy, including nearby Rome. Malaria would have made it increasingly difficult to feed the population and to maintain the Imperial army. [SOUND] The crisis in the military would put important harbors such as Olbia and Sardinia especially at risk. The Vandals were the main threat, but surprisingly, Eduardo Riccardi now thinks the Romans might have destroyed their own ships. He's uncovered evidence that the boats were scuffled. >> My opinion is that the fleet was burned after sinking. The traces of burning are only in one part, the other part is normal. >> Right. So you think that the boats were actually sunk, and then the bits that were still sticking out of the water were burned. >> Yes. >> Does this suggest to you then that these boats were deliberately sunk? >> Yes. >> And then the remains of them were then burnt in the water. >> I am almost sure now. >> And so, who do you think did that then? Vandals in the fifth century, coming from North Africa or the same Romans of the town, looking at the Vandals arriving. Both things are possible. >> It was an unequal struggle. The Romans, many of them meeting malaria for the first time, would've been vulnerable to the disease. While the Vandals of North Africa, having long been exposed to malaria, were likely to have possessed some immunity. The Vandals had a fearsome reputation. The fate of Sardinia was sealed. >> The Vandals, where they found resistance, seldom gave quarter. Careless of the distinction of age or sex or rank, they employed every species of indignity and torture. >> To lose Sardinia, so close and so valuable, was an ominous sign that the grip of the empire was slipping. The age of Rome was coming to an end. >> Plasmodium malaria, this is a new disease, which was terrific, traumatic. >> It was very common in some parts of Italy in the past, and particularly in Central Italy around Rome. >> To me, this is the most important impact on Roman Empire. >> It would kill people who had no immunity. It would debilitate others. It certainly had a debilitating effect on the population. >> As we got away from the dangers of malaria in our civilized societies, we forget, and we forgot what a terrible threat it was. But I think it was a major player, a major factor in the fall of Rome. There were barbarian invasions. There were economic hardships. There were many factors. But now we must admit that malaria was one of the major players. [MUSIC] Next time amateur archaeologists unearth a First World War killing field in Belgium. It's the biggest archaeological excavation ever carried out on the Western front. BBC Two follows the archaeologists as they keep one step ahead of the developers to recover weapons, personal possessions, and the remains of soldiers of both sides who fought on the front line. [MUSIC]
