On the door, which leads to the narthex from the south, a triple panel of mosaics are located. This panel of mosaics, which survived intact, has been found during the repair work carried out by G. T . Fossati in 1849. On the panel, on a ground of golden mosaics Mary is portrayed in the middle, on her right Emperor Constantine I, the Great, on her left Emperor Justinian are seen. The Virgin in the middle is portrayed as sitting on a throne that has no back to lean on, and she is holding the Child Jesus on her lap.
The Virgin’s feet are rested on a pedestal covered with silver mosaics and bordered with the embellishment of precious stones. The Virgin is seen, as is always the custom in Byzantine art, clad in a lapis lazuli garb. On the medallions franking her head, the monograms (MP -OY) are seen, expressing the words Mater and Theou, in other words, meaning “the mother of God”. The child Jesus seen on his mother’s lap, is making a sign of blessing, while holding a roll in his left hand. As to the expression on his face, it is an expression of an adult rather than a child. On the left of the Virgin, Emperor Constantine (306-337) is portrayed as proffering a model of the city to Mary.
Alongside with the emperor, and from top to bottom, it is inscribed with dark blue-black letters on a ground of golden mosaics, as follows: “Great Emperor Constantine among the Saints”. The founder of Christian Istanbul is portrayed here not in the garments of his period, but those of the period of the making of the mosaics; that is to say, of the Tenth Century .The emperor , who is seen wearing a dark coloured robe, and a shawl with gold and silver embroidery on top, wears a crown on his head. On the right side of the Virgin, Emperor Justinian, the Great, (527-565) is seen. The Emperor is proffering Virgin Mary a model of Hagia Sophia, that he is holding in his hands. These mosaics were made during the repair work carried out between the years 968 and 984, at the reign of Basil II.