Greek cross

[Greek cross]
A cross the four arms of which are of equal length. It is found only rarely in early Christian art. Later it was used on pillars and roofs of churches to denote that they were consecrated. It is much used in the decoration of Eastern churches. A Greek cross inscribed in a square formed the ground plan of the church of Saint Sophia, built by the Emperor Justinian in Constantinople in 537, and thereafter of many other Eastern churches.