The triple-aisled basilica of Ayios Stephanos in Kastoria is one of the oldest ecclesiastical monuments of the Balkan Peninsula. It has attractive tile decoration and wall-paintings, the earliest of which date to the 9th century.
These wall-paintings are of exceptional significance as an example of early painting reflecting a high level of iconographic and artistic attainment. The painting is flat and abstract, with strange colour combinations, and the compositions are geometrically arranged.
Some scattered dedicatory or liturgical scenes in the narthex and on the lower sections of the walls in the main body of the church date to the 12th century. Scenes on the ceiling of this part of the church must have been executed around 1200, while some others date to the 13th -and 14th centuries.