The synthronon is a structure in the apse at the back of the altar of an Orthodox Christian church that combines the bishop's throne/cathedra and seats for the clergy. During the Trisagion, the clergy assembles at the synthronon. The bishop's cathedra is centered in the set of chairs or tiered benches for the clergy. The synthronon came into use in the fourth century.
The psalterion, in the nave, that is thought by many to be the Bishop's throne was originally his stasidion, or choir stall, where he stood for the offices, such as Vespers and Matins. In monasteries, it is the Abbot’s stall.