The round dome building type, just like the basilican type was to be very important in the Constantinian period, and also in later times. And I show you, I remind you of some of the important domed rooms that we've looked at in the course of this semester, at the frigidarium at the Stabian Baths of Pompeii. At the temple of Mercury from the spa at Baia, the so-called Temple of Mercury. The the octagonal room of Nero's Domus Aurea, and the dome of the Pantheon here on the far right. There is no more important form in Roman architecture than the domed room, very characteristic of the Romans and a special gift that they passed on to posterity as you well know, and this, this type of building began to be explored, continued to be explored in the Constantinian period. I could show you several examples but I have chosen to show you just one of those. And it's the one that you now see on the screen in plan, a plan from Ward Perkins. This is the so-called temple of Minerva Medica in Rome. It's not a temple at all. It dates to the early fourth century AD. It's not a temple, but what it was was a pavilion and a garden. We know that an emperor of the third century AD by the name of Gallienus, G-A-L-L-I-E-N-U-S, Gallienus was responsible for building some imperial gardens in the third century AD. So this was another actually, you know actual this was another project that did happen in the third century AD. The building of some imperial gardens for the enjoyment of the emperors and of the imperial family. And it was in these gardens that were created in the third century that this pavilion was added during the Constantinian period in the early fourth century AD. And I show you a plan of that temple, that so called temple of Minerva Medica. Or this pavilion in the the so called Licinian, L-I-C-I-N-I-A-N. The Licinian Gardens. As commissioned by Gallienus. The Licinian gardens. And we see it here, and it's very interesting because although it clearly, it's a, it's a building made out of concrete faced with brick. And although it clearly is based on some of the buildings that I just showed you the round, the typical round structure with oculus. The frigaradia, the spa, the octagonal room, and the Pantheon. You can see that the architects of this period were still able to innovate and have gone further by creating not a round building, although at first it looks round, or an octagonal building, but a decagonal building. A ten sided building. And you can see ten, you can see radiation apses, nine and then the entrance way over here. So ten sided structure. If you look very carefully at the plan you will notice, though, that the that the uppermost apse, the one that is located directly across from the, from the entrance way, is a tiny bit larger than the others. So that gives the the building a little bit, even though its a round building, a little bit of a, a, of a longitudinal axis which is very interesting, this incorporation of a longitudinal axis into a round structure. You can also see the way in which the radiating apses, the two on either side, left and right are screened by columns in a way that we've also become accustomed to. And I believe that those columns, yes I'm pretty sure that those columns have a triple arcuation up above. So that yeah you can see in plan. A triple arcuation above that has, we've seen also is characteristic of, of late Roman architecture. Not only in the, in the private sphere as this is but also in the more public sphere. But going back to that longitudinal axis, look also at the entrance vestibule. This is another one of these narthexes, this cross, this transverse vestibule, in this case with apses on either end that is characteristic of these these early fourth century A.D. Roman, Pagan Roman buildings but is going to become a hallmark of Christian architecture, not only basilican architecture, that is, churches in the form of basilicas, but small religious structures in, that are done that are circular in general plan. So a very interesting plan in that regard. And a very innovative plan in the early fourth century AD. The building is still preserved. I can show it to you. It dates set, I could show you the outside as well as some details of the inside of the building, as you see here. this, it was made out of concrete faced with brick as I mentioned before. We are looking at the interior up toward the dome. You can see something very interesting here, which was, is the addition of ribbed of bricks to create ribs in the dome to give it something of a sense of a segmented dome, which is a building technique that we see sometimes in late Roman architecture. And you can also see, although it looks like it has an oculus, that's just because the, most of the roof has fallen in. It did not have an oculus. Instead the lighting was provided through these round headed windows that we see, very large round headed windows at the base of the dome. So again this move away in late antiquity from the oculus, to using these very large round headed windows to light the interior of the building. And this is a view of the so called temple of Minerva Medica as it looks today from the outside. Where you can see those red, same round-headed buildings. Where you can see those same sort of piers that are not so different from the ones that we saw at Trier used rather than columns to decorate the structure. Large round-headed doorway down here. very, you can see the scale, this is a pretty big pavilion in a garden, you can see its scale in relationship to the cars that surround it. So continued innovation in round architecture under Constantine the Great. And a building type that is going to have a long history in the Medieval period, in the Byzantine period and well beyond. I show you just one example of the impact that it had on later church architecture. This is the church of San Vitale, a very famous church in Ravenna in Italy that was that honors Justinian, the famous Justinian Theodora. It was built in the sixth century AD. And I think you can see by looking at a view of the exterior, a plan and also a view of the interior how important architectural experiments under the Romans were for buildings like this. The massing of the outside, the geometry, the interest in geometry, simple forms. Round headed windows. So similar to the aesthetic that we saw in [UNKNOWN] or in the basilica at Trier. The plan above in this case an octagon, with a central area with radiating alcoves. Very similar to the sorts of things that we see not just in the dome of [UNKNOWN] but also in the temple of Minerva Medica. And you can see the narthex here, just as we saw in the temple of Minerva Medica. And you can see in this view of the interior, for example, the triple arc arches on top of the two columns. All of these motifs taken over clearly from Roman architecture, ancient Roman architecture and exploited in the medieval and Byzantine periods.