 So, Ilya, I know that you want to talk about archaeological discoveries, but you also know a lot about military history, so why don't you tell us how these two belong together? You cannot see them at the moment, but actually I have two heads. That's right. I wrote a book about 18th century common soldiers, and my other big field is motivation, why people do things, what prompts them to do it. Today, however, I will be speaking under my medieval hat. I'll be telling you about Crusader Jerusalem and its art, and it is, in fact, a project I'm working on at this very moment. So, exciting archaeological discoveries that are happening right now by Ilya. Very exciting. Listen forward to a talk. Thank you, Andre. Thank you for this kind introduction. In my talk today, I will take you to Jerusalem. Now, Jerusalem, I believe, needs no introduction, a city with a long and illustrious history, and those of you who follow contemporary events in the news are very likely to have heard it as well. Jerusalem is also one of the world's most important religious centers. It is the holiest city for Judaism, third holiest city for Islam, and also the holiest city for Christianity, and this is with Christianity, or more specifically with this church, the Church of the Holy Sepulchre that my talk will be concerned with. Now, the Church of the Holy Sepulchre is built over a cluster of incredibly important holy sites in the early days, in which crucial events have occurred during the early days of the Christian religion. On your right, this is the hill of Calvary where Jesus was crucified. On your left, this is the tomb where he is said to have been buried and where we, not that long ago, we celebrate some of us celebrated Easter. This is also where he rose from the dead, so the site of the resurrection. All these sites, as well as a few others, important, but not as much, are located within that church, and for that reason, because of its religious importance, as well as also its long and interesting architectural history, the church has been drawing ever since it was built. Pilgrims, visitors, tourists, and explorers. Now, as I already mentioned, the church has a long architectural and artistic history. The first church on that site was built in the 4th century, so 600 years ago. This church was destroyed about 1,000 years ago, and another one was built. The building which you mostly see today was built in the Crusader period, so the 12th century, 800 years ago. Now, not every single element within that building is 800 years old. Some of them are older and have been reused. And also the church has underwent numerous reconstructions and conservation efforts. This being said, the basic structure is more or less 800 years old. Because of its history and its religious importance, it is one of the best documented buildings on earth. You see here a database which I have compiled. It's just a small part of it, and for the benefit of those who are sitting in the back rows, this just shows descriptions of the church made during 50 years from 1650 to 1700. There are 43 individual authors in Italian, French, German, Latin, Dutch, and Russian. Almost every year, someone has visited the church and wrote a description of what they sow. Between 1300 and 1900, there are over 700 such accounts. And in the entire history of the building, well over a thousand. Every change, every new building work, installation of various new elements, is usually witnessed and documented. When from about 150 years ago and onward the birth of archaeology as a new scientific discipline, the person on your left is Count Melchior de Vogue. The father of crusader archaeology and crusader art history. His most important initial work was on the Church of the Holy Sepulchre. And many of his findings, in spite of the fact, they're quite old by now, still hold. On your right, Conrad Schiek, another incredibly important scholar, actually a self-made man, had no university education, carpenter and missionary by education. Arrived at Jerusalem and in his mid-40s, started visiting the church, making plans, but in 50 years he became the most knowledgeable person in town on the church and its history. And much of what we know about the church, we owe to his first plans and measurements. So those are just the first two major scholars, many have followed, many, many more. I'm speaking literally about hundreds of scientific books and articles. So as you might expect, with such a comprehensive general coverage, is there anything new to be found? Is there anything new to be discovered in this building? I would say yes. Well, two years ago, as part of yet another round of reconstruction work, it was decided to re-examine, yet again, the numerous architectural elements which were spread, which are spread over the church in its different corridors and cellars. One of them was an inconspicuously looking stone plaque, which stood against the wall at one of the side corridors. The plaque was considered to be so unimportant and inconspicuous, we almost have no photograph of it as it stood in its original place. I could only find this on Wikipedia. To the best of our knowledge, the plaque was lying, or standing I must say, therefore in recent memory, so at least 50 years. Now the flat surface of this plaque has been tempting numerous visitors and tourists to write their names. So the plaque was actually known in the church to the local clergymen and to the local tourist guides as the graffiti stone. Now imagine our excitement when the plaque was turned around and we saw this. Now, one doesn't need to be an art historian or an archeologist to understand straight away that this is a major discovery. This is in fact, in spite of the decay, it's a highly elaborate work of art. You see here a pattern of one large circle in the middle surrounded by four smaller circles on the side and it was probably a second element like this in the part of the plaque which broke away. We can actually identify it. This type of medieval artistic ornament is called cosmetesque ornament and this is how our plaque might have looked like in its original state. There are two elements here, one symbolic and one material. The symbolic one is that figure with the five circles. It's called quincox. The quincox has a meaning in Christian, in medieval Christian cosmology. It symbolizes also the infinity of the creation and the five wounds of Christ. It will be used to decorate the most important parts of the church. The material element, how this ornament was in fact executed, the large circles were usually filled with one piece of precious marble like red porphyry or green serpentine. The smaller bends on the side were filled in a technique called inpristation or inlay. Small bits of colorful marble were inserted as if as mosaic to create highly elaborate patterns. Now, there are other types of medieval art which employ the quincox to decorate as an ornamental pattern. There are other types of medieval art which use the inlay technique but this particular combination of the quincox and the inlay technique points us directly to medieval Rome. The medieval Rome at that time is not just a major European art center, it's also a major religious and political center. The cosmetic technique is used almost exclusively in ancient Rome. The master craftsmen who employ this technique have a monopoly from the Pope. You can see one of them on your right, Innocent III who was a major art patron who has commissioned an avenue of big projects employing this technique. For the Pope, the role on earth is not just the head of the Catholic Church. They're not just a spiritual authority but they're also a major temporal authority. They're not just equivalent, they're superior to kings and emperors. To demonstrate this authority, they commissioned highly elaborate works of art and the use of cosmetic technique is usually kept for the papal state. You see in the column the number of sites where this technique is employed. Over half of them are in Rome. Over 80 churches are decorated by cosmetic technique. In Latium, this is the core area around Rome which is also ruled by the Pope. We have another 50 sites. In the rest of Italy, put together, we have 12 sites at all. The only site outside of Italy where cosmetic technique is employed is Westminster Abbey in London. It's a very clearly a Roman technique and Italian technique which points us to a very specific place and a very specific time. Discovering it in Jerusalem thousands of miles away, I can tell you it was quite a discovery. Going back to our piece, let's have a quick look at it again. First of all, you see Mark with the red arrow. A few small bits of marble. This indicates that the piece was originally in late, in that style. You see, marked with green, a sunken frame. A part of the plague is a little deeper. It's lower part here marked with yellow. It's smoothed out. It's not decorated. And then if we look on the side where all the graffiti are, you see here on the lower side the remains of what we would call a protruding lip or a back step which indicates that that part of the plague was supposed to be much wider. You see here a reconstruction of how this plague probably has appeared in its original form drawn by my colleague Amitri M, the city archaeologist of Jerusalem. Now, what this plague could have been. It was clearly a very important piece of highly decorated church furniture. Well, research on the subject is still ongoing. However, if I could just point you to a recent article in the Smithsonian Magazine which makes, which mentions our initial hypothesis, what this plague might have been used for. Nevertheless, the main point of my talk is it's not what the plague is about. The plague was lying there in plain sight at least for half a century and no one has bothered to turn it around. The age of great discoveries in archaeology, even in the church of the Holy Sepulchre, is not yet over. Thank you for this great talk and I already saw some people suspiciously looking at the plates on the floor right here. So, are there any questions for our speaker in this context? Don't be afraid. Over there? Yes, please. If it's Cosmotesque Ornament, it's 12th or 13th century because for much of the period Jerusalem has been ruled by the Muslims, we need to narrow it down to the period when it was ruled by the Crusaders, so by Christians, so 12th century. We think we can date it more precisely, but we're still working on it. Any other questions? Don't hesitate. Yes, wait a second. If it was a graffiti stone, then why did you try to turn it? Like, what was the idea behind it? There was a big restoration work going in the church and part of the tomb of Christ has been dismantled in order to be put together again once it was structurally sound. In order not to confuse elements from the tomb with other pieces lying around the church, it was decided to decrement them all. And this was part of that project. It was a side effect. It was not planned initially. We have time for one more question here. Over there already, yes? Over there. And don't worry, please engage our speakers during the break that follows up to ask any unanswered questions. Yes, please. So as far as I understood, this was more a coincidence of how you made this discovery, right? With this turning... It was a chance discovery, yes. So what is the ordinary way to make a discovery? The... Ordinarily, you have a site. You have a big team. You start digging atop and coming with things from the ground. That's one scenario. The second scenario that you read very carefully, all the numerous books and articles, you come to the church, you look at the elements which are already known and you try to reanalyze them. The problem with the second approach is that it puts you in a state of mind which focuses on what is already known rather than looking for things which were not noticed before. Well, I think this is a take-home message, definitely. I see in the front there was one question and we have the microphone right next to him, so let's answer that question as well. Thanks. I'm curious if at this age, for things like these churches that are not billions of years, does it still make sense to use maybe the radiological analysis to figure out approximate age of things at least? Were some of this done for this church and were there any inconsistencies in terms of ages of different pieces of... I will try to reformulate the question in case it is not clear. So, have any newer technologies been used to image this old church and what are the resulting findings? Extensively, archaeometry, so dating of material, various types of 3D scanning, and not with these graffitis, but with more ancient ones, you can actually see various layers of graffiti and writings on the walls of which one came sooner or later. Now, this is not my field. I'm not a specialist. I'm working with people who are much more expert in this than me, but absolutely yes. With our particular stone, we are hoping to take some samples of the marble and to determine its precise origin. All right, then again, a big applause for Illa.