In front of the Edicule opens the space reserved to the Greek Orthodox, the Katholikon, occupying the center of the church where the Crusaders had built their Choir of the Canons.
The Brotherhood of the Holy Sepulchre, formed by Greek Orthodox monks and presided over by the Greek Orthodox Patriarch of Jerusalem, has the responsibility for the account of the Greeks for taking care of the Church of the Holy Sepulchre and carries out most of its own services in the Katholikon.
The dome, recently adorned with Byzantine-style mosaics depicting Christ Pantocrator surrounded by the bishops and patriarchs of Jerusalem, is supported by arches joined with pendentives to the Crusader columns on which the Evangelists are depicted; at certain times of the day rays of light enter through the windows, cutting through the atmosphere and creating suggestive effects.
At the rear of the Katholikon is the iconostasis, divided into two by a patterned series of red marble arches and columns, behind which are located the traditional Greek Orthodox icons. On either side of the iconostasis are the two Patriarchal thrones reserved for visits of the Orthodox Patriarchs of Antioch and Jerusalem. To the rear of the iconostasis, beyond a sail vault, is the Crusader apse, whose ribbed ceiling is interspersed with windows that illuminate the church.
A rose-colored marble basin containing a circular stone marked with a cross is known as the Omphalos, the Navel, the center of the world: based on various Biblical references, this was seen to be the geographical center of the world that came to coincide with the site of the divine manifestation.
This notion was already present in the Jewish religion which considers the entire city of Jerusalem to be the center of the world; for Muslims, the center of the world is marked by the rock at the center of the Dome of the Rock. In the Church of the Holy Sepulchre the cross of Christ is the center of the world from which the arms of the Savior extend to embrace it in its entirety.
During the excavations carried out in 1967-68 beneath the floor of the Katholikon, the Greek architect Athanasios Economopoulos discovered the apse from Constantine’s Martyrium Basilica, near the point of the current Crusader apse.