On the upper floor of Hagia Sophia, the walls of the gallery at the south, are embellished by the mosaics considered to be the best in Hagia Sophia and the most famous one in the world. These are known as the Deesis Mosaics.
On these mosaics, Virgin Mary and John the Baptist (Ioannes Prodromos) is seen asking Jesus for intercession for humanity on the Last Judgment Day. The bottom parts of the panel of 6 x 4.68 meters dimensions have unfortunately deteriorated due to the air circulation from the window. But even the remaining parts are enough for them to be considered as one of the most important works of Byzantine art.
On the panel, are located a big Jesus in the middle and the Virgin on his right, and John the Baptist on his left, all of them seen within the golden background. Jesus, who is here depicted as seen from the front, has a halo with a cross at the back of his head. Jesus, while making a sign of blessing with his right hand, holds abound Holy Book in his left hand. The bottom parts of the Virgin Mary, who is situated at the right side of Jesus, are badly deteriorated. Mary is shown in three-fourths profile and only her head and shoulders have survived the wear and tear. She has a human expression on her face and looks downward. Both the names of Mary and Christ are written in abbreviations in Greek on both sides of their heads respectively.
John the Baptist (Ioannes Prodromos) stands on the left side of Jesus. He is shown in three fourth profile, just like the Virgin, and his first name is written in abbreviation from top to bottom, but Prodromos is written fully.
As it is related in the Bible, John the Baptist spent his life in the desert, far away from the favors of the world, and this isolated, solitary life is reflected on the expression of his face. On the faces of both the Virgin and the Baptist, one can read the suffering of human beings on the Last Judgement Day. They symbolize that salvation is by and from Christ on that fateful day. Christ, on the other hand, appears on this great day of judgment as an entity full of tenderness and kindness, and exalted to reach divinity.
The well-chosen colors of the mosaics is a splendid example of the indication that the main principles of the pictorial arts in the Early Ages, continued to live in Byzantine art and in the entire Middle Ages. The Deesis mosaics, which were brought into daylight through the meticulous work of Thunderwood in the years 1934- 1935, are considered by the experts of the history of art, as the beginning of the Renaissance in the Byzantine pictorial arts. Although some historians j consider the Deesis mosaics as belonging to the Eleventh, and some others to the Twelveth, and still some other Byzantine history, of art experts, attribute them be of the Thirteenth Centuries; it is generally accepted that they date back from the Twelfth Century.