Historical Context
Theodosiopolis, the brothers' hometown, was the chief military stronghold on the eastern frontier of the Byzantine empire — long contested between Byzantines, Persians, and Arabs. An Umayyad general had taken the city around 700/701, making it the seat of an emirate, so that by the brothers' lifetime it lay under the rule of a Muslim emir.
Despite this rule, the surrounding region held a substantial Christian population, bordered by Armenian and Georgian Christian territory and lying close to Byzantine lands. This frontier setting — a Muslim-governed city ringed by Christians, near Georgia and Byzantium — frames the brothers' situation: a Muslim-born family in which a Georgian Christian mother could pass the faith on in secret.
The journey to the capital places the martyrdom firmly in the reign of Nikephoros I, who ruled as Byzantine emperor from 31 October 802 to 26 July 811. (Some accounts attach the surname Phocas to this Nikephoros; that is a confusion — Nikephoros I, formerly finance minister under Empress Irene, was not of the later Phokas family.)