The church of the Panagia Piskopiani, which is also re ferred to as Episkopi or Panagia Protothronos, is located at Piskopio or Episkopeion on Syros and is virtually unknown in the bibliography, despite its considerable interest.
The study of it adds another example to the churches of transitional cross-in-square type already known, on an island whose history and architecture in Byzantine times are obscure.
The fact that the west corner bays of the monument do not communicate with the west arm of the cross and are slightly shallower than the east ones assigns the church to the version of transitional churches which Domi nique Hayer classes as transitoire court. Reservations should be expressed, however, with regard to this issue, since it is not certain that openings did not exist originally in the walls upon which the vault of the west arm rests, given the extensive recon struction the building has undergone, due to its conversion into a church to serve the Roman Catholic dogma.
In the course of these alterations, it seems that the three semicir cular conches of the sanctuary of which only that of the diakonikon survives were abolished. An entrance to the nave was arranged on the east front, while the position of the sanctuary was transferred to the west front.
The dome is square in shape with rounded angles and slight tapering of the tympanum. The proportions are heavy and the morphology of the facades refers to Byzan tine church building in the Aegean Islands. The entrance doorway possibly had a doorframe, which has been placed in second use in the now ruined bishop’s residence, exactly opposite the church. This is a marble frame, possibly of seven teenth-century date, with lintel supported by lateral can tilevers, which have been chipped away.
On the sill of the north window and on the floor are two fragments of a Byzantine closure panel decorated with the familiar motif of a lozenge inscribed in a rectangular frame, with five circles in the empty spaces, possibly of the eleventh centur.
Although it cannot be demonstrated securely that the clos ure panel comes from the iconostasis of the church, both the typological and morphological features of the monument also advocate a date in the eleventh century, with some re servations. Although we are unable to draw definite con clusions, this is certainly a Byzantine church with early features, among which is its name, Panaghia Protothronos.