arsenitai
Followers and supporters of patriarch Arsenios Autoreianos, who had excommunicated Michael VIII Palaiologos. Michael managed to get rid of Arsenios in 1265; from that time, Arsenios’ followers were at odds with the Patriarchate of Constantinople, refusing to recognize Arsenios’ successors to the patriarchal throne. Politically they supported the Lascarid dynasty and opposed the dynasty of the Palaiologoi. The dispute was resolved in 1310.

Brickwork patterns
the decoration of the exterior walls of Byzantine churches with bricks, or other enclosed ceramics in various shapes and combinations.

cross- (groin-) vault
A vault formed over square or rectangular spaces by the interpenetration of two barrel-vaults of equal hight and diameter. The lines of the intersection form a diagonal cross.

cross-in-square church
Type of church in which four barrel-vaulted bays form a greek cross; the central square of their intersection is domed. The cross is inscribed into the square ground plan by means of four corner bays.

donor
Whoever subscribes, financialy, to the errection of a certain structure (monument etc). In the case of the buildings, donors might lawfully relate to them via a special connection (usufruct or other).

exonarthex (outer narthex)
The transverse vestibule or portico preceding the narthex of the church.

katholikon
The main church in a monastic complex, heart of the monastic activity.

pastophoria (parabemata)
Rooms or places that as a rule surrounded the apse, next to to the Holy Bema, of the Paleochristian or Byzantine churches, namely the diakonikon and the prothesis.

protovestiarios
(and protovestiarites) Honorific title given to high-ranking officials and future emperors during this period. The protovestiarios was originally responsible for the imperial wardrobe, but in the 9th-11th centuries the holders of the title could command an army or conduct negotiations with foreign states.

recessed brick technique
A masonry technique in which bands of wider and smaller bricks are alternated. The smaller bricks rows are slightly recessed and covered with mortar, thus creating an alternation of red (brick) and light-colored (mortar) surfaces.

typikon
Foundation document of a monastery compiling the rules regarding its administrative organization and liturgic rituals, as well as the comportment inside a cenobitic monastery. The monastic typika could also include the biography (vita) of the monastery founder along with a catalogue of the movable or immovable property of the monastery. They constitute an important source for the study of the monastic life, while at the same time they shed light on many aspects of the Byzantine society. The liturgical typika were calendars with instructions for each day’s services, liturgical books with rules arranging the celebration rituals.