Aya irini, as now know or the Church of Saint Irene is both a important Byzantine churc from the point of wiews of architectural history and is at the same time second largest church after Aya Sofia.
The church lies next to the walls of Topkapı and was used as an ammunution depot until Fethi Ahmet Paşa, Marshal of Tophane the had it opened as museums in 1850. In 1869 it became the Museum of the Palace Müze-i Hümayun.
In 1875, the works in this museum were tranfered to the Çinili Köşk. The curch, which was built by Constantine the Great who consecrated it to ”Divine Peace” was burnt down during the Nika revolt of 532. The emperor Justinian had the building rebuilt and enlarged. It later however was much damaged during the earthquake of 732 and during the latter part of the 8 century.
The building is a domed basilica, the dome measuring 15 metres in diameter and 35 metres in height. From the exterior the dome appears to be rather squat and irregular, where as in fect it is quite spherical. Many of the 20 windows in the drum were later closed up.
From the exterior, the apse appears to be triple-facaded. It is semi-domed and has a gilded floor. During the period of Iconoclasm figural mosaics were forbidden, only cruciform motives were allowed. The building underwent restoration at the apse during that period. The dome was born by piers linking the main nave to the transepts.
It had three tunnel-vaulted naves with galleries over the main piers. The stone work of the wall is typical.
Today the building which is connected to The Ministry of Culture is not only an important architectural monument but is also important as the first building to be used as museum in Turkey.