 Our subject, in this case study, is imperial porphyry and the way in which it was utilized by the Romans. And what you see here is a wonderful sample, fairly small, of imperial porphyry from the one and only quarry where it was found in the ancient world. Now, porphyry of a similar color has been found in another modern quarry, I believe, in Poland. But as far as art historians are concerned, there is only one imperial porphyry. And that is the reddish-purple porphyry, like what you see here, that was exploited by the Romans for very important symbolic purposes. And so that's what we're going to discuss right now. This is a wonderful map that I'm going to have provided for you as a link. But what I want you to notice about this map is it shows the stone quarries of ancient Egypt. You can see the Nile Delta up in the north and Cairo. And what I want you to notice is take a look at the pink area just to the left of the Red Sea. These are the Red Sea Mountains, a mountain range, or Red Sea Hills. It's a mountain range that is between the desert and the Red Sea, and was relatively difficult to get to. And the area that you're going to see here with my purple dot, this is Monts Porphyrites, the location where they found imperial porphyry. So that's what it looks like right there. And there again, that's Monts Porphyrites. Without my dot, you can see that there are numerous hardstone quarries. Those are the red dots shown here. And here again is the site. Here's a closer map showing the Monts Porphyrites area. And this shows the sort of the modern setup. If you were to go visit the site today, you would likely fly into El Guna. And then take the trail up to the site, probably in Jeeps and 4x4s. But the point of all of this is that this was a very difficult site to reach. And caravans had to go up into these inhospitable desert mountains and ship out this porphyry. And the Romans had to create a pretty substantial network of forts and wells and guard posts and other things along the way in order to facilitate the continued mining of this imperial porphyry. And we know that it was mined from the 1st century CE up into the 5th century CE. So it was only mined for about 500 years, actually a little over 400 years. And it was an incredibly massive undertaking to acquire this stone. Once it reached the Red Sea, then it had to be shipped to Rome. And so that would be partly by water, partly by overland. The Suez Canal did not exist at that time. So there were all sorts of difficulties that were inherent in the shipments of imperial porphyry back to Rome. I'm a bit of a Google Earth junkie. I love to look at different sites on Google Earth and get a sense of them. And I think if we look at Mons Porphyrites in satellite view, you get a really good idea of just how inhospitable this terrain truly is. The Roman fort site and the well for the quarry would be some of the primary areas for acquiring the imperial porphyry. The Roman fortlet and the Roman fort that you see, the Roman fort at Badia, those would be to help with the safety and the security of the caravans that would be shipping these stones. And also bringing in supplies for the quarrymen. And we know that these were not slaves working in this site that they were very well paid and extremely well taken care of. And that's something that seems to characterize a lot of the quarrymen, not just in Roman times, but also in Egyptian times. This was a highly skilled labor force that had to be supported. So how do we know that Mons Porphyrites was discovered in the year 18? Well, archaeologists, when they investigated the site in the 19th century, discovered and recorded this memorial slab, which in Greek tells us that Gaius Cominius Logus, who was the legionary who discovered this site, basically dedicated this plaque to the sort of an Egyptian Roman hybrid god, Pa-min, and also to Serapis. And so it says, Gaius Cominius Logus, who discovered the quarries of the porphyry stone and Connecticutis and black porphyry and also found multicolored stones, dedicated a sanctuary to Pan and Serapis, very great gods for the well-being of his children, the fourth year of Tiberias Caesar Augustus, Ep. 29. So we have the year and the month, we have descriptions of the stone, and what he would have done is at least surveyed this mountain and sent samples of stone back to Rome. And of course, we know that the Romans considered this to be worth exploiting, which is why we have all of the quarries on the site. We don't know what the Connecticutis stone is like, but black porphyry is something that you saw an example of in your earlier readings prior to these case studies. And then the porphyry stone that they're referring to is probably the imperial porphyry. And there are a number of other types of stones found on this mountain and also the adjacent mountain, Mons Claudianus, that were both used a lot by the Romans. I should mention the figure of the god here. This is the Egyptian god Min, who is being shown in combined aspects with the Roman god Pan. And one of the attributes of Min, as you might have guessed, is an erect phallus. Something that you should understand is that the Romans loved exotic colored stone. And so what we're looking at here is the floor of the pantheon in Rome, the probably the greatest and most famous of the temples built by the Romans in that city. And here on this floor we're seeing different types of veined white marble. Some of these would come from a place like Carrara, like the marble that is really bright white with the sort of bluish stripes. We also have what I believe is called giallo antico or antique yellow stone. You see this big roundel here in front of you. That's imperial porphyry. And we can see just a bit of additional imperial porphyry at the bottom left in my photo. There's also rosso antico or antique red to the right. And I think you can see other colors of stone here. There are sort of greenish and grayish roundels as well and different types of patterns of marble. And we have to imagine that all of the pavements in forums and basilicas and temples and palaces would have had expensive stones. And Romans who couldn't afford expensive stones paid painters to imitate expensive stones and decorated with those. So there was a real taste for this. And part of the message of having a collection of these exotic colored stones was a way for the Romans to show their power and their influence in the world because they were acquiring these stones from all over the world. The giallo antico, as I believe, comes from North Africa. The porphyry from Monts Porphyrites. The marble would have come from as near as Carrara or as far away as the Greek islands. There were numerous sources for stones throughout the empire. And the more colorful, the more exotic, the more popular they were with the Romans. Of course, some of the most elaborate stonework was reserved for the emperors. And imperial porphyry is something that is always associated with the emperors. Back at the pantheon, the person who commissioned and possibly even designed the pantheon was the emperor Hadrian. So it's not surprising to see roundels of imperial porphyry on the pavement of that floor. Here what we're looking at is some examples of marble inlay on the left and then some pieces from colored marble inlay on the right from the Palatine Hill in Rome. And the Palatine Hill is a hill up above the Roman Forum where all the imperial residences were built from Augustus onward. Emperor Augustus had a relatively modest house, but then succeeding emperors built extremely elaborate palaces on the site. And it was elevated over all of Rome with a view on the one side of the Forum and on the other of the Circus Maximus where the great horse racing took place. And one of the palaces was actually designed so that there was a private box for the emperor accessible from the palace. So what they would have done in these palace rooms was decorate the walls and the floors and even the ceilings with these incredible intricate designs made of colored stones from all over the empire. And one of the really fascinating things you can see if you go to the Palatine Hill Museum today, the antiquarium on the Palatine Hill. It's usually open only in high tourist season in the summer. They have a map on the wall that shows where the Romans acquired all of these different types of colored stone. And so here what you're looking at that green is the green porphyry from Greece, the porphydo verde antico that I mentioned in the course pages prior to the case studies. On the right you can see imperial porphyry that was used as some of this inlay. And I think you can also recognize some giallolo antico, some of that antique red or gold and then some beautiful reds here. And then though the white could possibly even be ivory. It looks like it's not stone at all. The Romans made many, many works out of imperial porphyry, bathtubs, ponds, fountains, statues in multiple colors of marble, the inlay that we've seen, all sorts of things, columns. But we're going to look now at probably the most famous example of imperial porphyry in use. And one of the examples that is always part of art history courses. And that is this sculpture here and you can see that it's been split into two parts and applied to the side of the building. It is now at the Basilica of San Marco in Venice. But it was originally in what is today Istanbul, what was originally the city of Constantinople. And this sculpture represents the four tetrarchs. And so I'll tell you first what the tetrarchs are and then we'll get into why porphyry is so important and also some of the ways in which we can see tool marks and the way that it was worked in this work. In order to understand the tetrarchy, you need to understand the tetrarch sculpture. You need to understand what the tetrarchy was. And so I have a map here that is going to take away some dates. You're going to see colors changing as I go. But essentially what happened was that in the late third century, early fourth century, the Emperor Diocletian came to power. And he came to power after a series of really weak emperors who had no clear succession had kind of all ruled in sort of a chaotic state. There was like a 20-year period in which there were about 40 emperors prior to Diocletian. And different armies and groups would say, hey, our guys, great, let's make him emperor. And so they would march on Rome and take over. And that person would manage to rule for maybe a few months. And then the next group would raise their particular favorite as leader and march on Rome. And so what Diocletian did was he divided up the Roman Empire into two halves, east and west. And then he divided each of those halves again in half with a chief emperor and a lieutenant emperor as the rulers for each side. So the chief emperor in each of this, this was called the Tetrarchy because it involved four rulers. There was an Augustus, who was the chief emperor, and his Caesar, who was his co-emperor and designated successor. And what you're seeing as our map ticks away here is that it started out very cleanly with four individual emperors. The two Auguste and two Caesars ruling together. And then here's the first Tetrarchy in 293. And we see we have Galerius and Constantius as the two leaders of the second Tetrarchy in 305. But then we start to see problems with the succession. The people who are appointed as Caesars aren't particularly happy with their lot. They decide they want more power. So Constantine in the west sort of works to defeat his rivals. We see similar tensions in the east and the whole system finally broke down. But what's important for us was that the initial idea was that these four co-emperors, the two Auguste and the two Caesars, were meant to be seen as a unit ruling the Roman Empire together peacefully. Now let's get back to the corner of the Church of San Marco in Venice. When after Constantine took over as sole emperor at the end of the Tetrarchy, he established a new capital at Constantinople. But prior to that it was a city called Byzantium that was fairly important within the Roman Empire. And this sculpture of the Tetrarchs came from that city of Byzantium. It was looted by crusaders in the 13th century who took it and brought it back to Venice. And if you look at the far right in this slide you will see one foot of one figure that doesn't match any of the others. And that is the piece that didn't make it from Constantinople or modern-day Istanbul back to Venice. And the matching foot has actually since been excavated in that city. We know that this sculpture was originally meant to stand as a monument in that city. That said, we don't know which set of Tetrarchs are supposed to be represented here. It could be the first Tetrarchy with Diocletian. It could be the second Tetrarchy. We just don't know. But that actually doesn't matter too much because it's really a celebration of the concept of the Tetrarchy. So remember for Diocletian the whole idea is to split up the empire so that it's easier to rule it in two halves. And then you have two chief emperors who are cool rulers. And each one of them is partnered by a lieutenant emperor. And when that chief emperor either dies or retires the co-emperor, the lieutenant emperor takes over from there and then appoints a new lieutenant emperor. And so the succession is assured. So looking more closely at the statue you'll notice that we have these emperors in pairs. And they're also set up grouped so that one emperor is embracing the other. So there is, and we'll go back here to that general view, there is an active member of the pair who is reaching out to embrace the other emperor. And then there's the more passive one who is being embraced. Aside from that they're dressed in the same type of clothing. They have armor on and cloaks. Each one is gripping a sword. The sword has an imperial eagle on the hilt. And again you can see the color and texture of this porphyry. Now what I find very interesting here is that in each of these pairs the active figure is also the bearded figure. And historically beards are a sign of power and particularly of masculine power. So my suggestion would be that the active one, the one who is reaching out and embracing the other and has the signs of a beard on his face. You can see here the punch marks that the artist used to simulate stubble on the one, whereas the other one has a very smooth, polished, youthful face. I would say that this bearded active figure is probably the Augustus, the chief emperor. And his younger companion who is beardless and who is also submitting to that embrace is the lieutenant, the Caesar in this pair. Here we have a coin representing the tetrarchy. And what you see here are four figures all participating in a sacrifice, which you have in the center. They're standing in front of like a fortified gate or enclosure. And then in between the four of them that thing that you see is kind of a raised brazier upon a tripod. So it would be something used to burn offerings. And then the fragrant smoke would go up to the gods. And so here we're seeing the four tetrarchs, again, with very little distinction between them that you can't tell who is who at all on this coin. But the point is that they're all participating together for the good of the Roman people. The way that you do well by the people is that you keep the gods happy. And if the gods are happy, then your kingdom prospers. And that's a longstanding ancient belief that the Romans also believed. So here in this work, the tetrarchs, we have a piece that by the fact that the entire thing is carved out of porphyry is meant to tell us, first of all, this is something imperial. And then when we look at it more closely, we are meant to understand that these are four emperors who are working together with very little differentiation between them for the good of the empire. Also, the hardness of the porphyry is symbolic here as well. Because think about it, if you want to make a propaganda statement about a new governmental system that is intended to last forever, why not come up with a stone that is so hard that it's considered almost impossible to work? So there are numerous things going on here symbolically both in the way that the stone is carved and also in the nature of the stone. And that all works together to send us this message about the tetrarchs.