Very few wall-paintings of the dark ages have survived to this day. There is one extant wall-painting in Ayios Demetrios, with unique theme -- so-called historical -- showing an emperor's triumphal entry ('adventus') into a city.
On the basis of the historical sources it is believed to depict the 'adventus' of the emperor Justinian II into Thessalonike after his victory over the Slavs. The work is dated to the 7th or early 8th century.
A rare aniconic decoration was discovered in 1933 in the church excavated south-east of the 'forum' (Roman market place) of Thessalonike. The composition, dated to the first half of the 9th century, consists of large gem-studded crosses and palmettes.