A synthronon is the semicircular stepped seating for clergy in the apse of a Byzantine church.
The seating was arranged behind or around the altar area, with the bishop’s throne occupying the central or most prominent position. It visually expressed the hierarchy of the clergy and linked the bishop to the liturgical space of the apse.
The term comes from Greek and refers to a shared throne or seat. Archaeologists identify synthrona in several Byzantine churches, although surviving examples vary in size, position, and preservation. Some were built into the apse, while others were reconstructed from architectural remains.
A synthronon should not be confused with the bema, which is the sanctuary area itself, or the narthex, which is the entrance hall. These terms describe different parts of the church’s plan.