Donnerstag, 29. April 2010

Hagia Sophia and Domed Architecture

Hagia Sophia

The name Hagia Sophia comes from the Greek Ἁγία Σοφία and means Holy Wisdom. The emperor Justinian gave two scientists - Isidorus and Anthemius - the task of designing Hagia Sophia (AD 532 - 537), which was to be the new cathedral of Constantinople.

The two scientists started their design by dividing the square-shaped church into three rectangles:

In the middle of the church, they built stone piers - which were set out in the form of a square. These piers were to support a brick dome. The dome measured 31 metres in diameter. Four huge arches were built from the tops of the piers and in the spaces between the corners of the arches and the dome, pendentives* were extended. This meant that the dome had a circular base.

Small arched windows were cut into the base of the dome and the dome was reinforced with ribs and buttresses.

For support, smaller half domes were placed against the arches.

The dome was covered in mosaics and seemed to float - the piers could not be seen.

Hagia Sophia took five years to complete, but the speed at which it was built may have rendered it unstable. In the sixth century an earthquake caused the dome to be destroyed. The dome was replaced only to have partially collapsed a few centuries later.

When the Turks invaded Constantinople in 1453, Hagia Sophia was turned into a mosque with four minarets.

* A pendentive (as shown in green) enables the construction of a circular dome over a square room or an elliptical dome over a rectangular room.