dome
A characteristic element of Byzantine architecture. The dome is a hemispherical vault on a circular wall (drum) usually pierced by windows. The domed church emerges in the Early Byzantine years and its various types gradually prevail, while they are expanded in the Balkans and in Russia.

domestikos
A term that during Byzantine times denoted a wide array of ecclesiastic, civil and military officials. In church hierarchy the domestikoi were in charge of special groups connected with liturgical rites, such as lectors, sub-deacons but mainly cantors. In the military chain of command during the 6th, 7th and 8th century the domestikoi were the commanders of the tagmata, the regiments under the direct command of the Emperor.

niche
Semi-circular recess on the surface of the wall.

opus sectile, the
Technique of floor or wall decoration. Thin pieces of polychrome marble are carved or joined so that a decorative motif could be depicted.

portico
A porch or a structure consisting of a roof supported by columns or pillars, leading to the entrance of a building.

stylobate
The top step of the crepidoma (the stepped foundation of an ancient Greek building) from which the columns rise.