The Church of Saint Nicholas Orphanos is an early 14th-century Byzantine church in Thessaloniki.
The church's name, 'Saint Nicholas the Orphan', is first attested in the 17th and 18th centuries, and presumably refers to its otherwise unknown ktetor (founder). From its interior decoration, the building is dated to the period 1310–1320. The church originally formed part of a monastery, traces of which (remnants of a gate) survive to the east.
The church was originally built as a simple, single-aisled edifice with a wooden gabled roof. Later, aisles were added on three sides. They form an ambulatory, under whose floor several graves have been found. The masonry features irregular layers of brick and stone, with a few ceramics on the eastern side and brick decoration on the eastern and western sides. In the interior, the central aisle is connected to the others with double openings decorated with reused late antique capitals. The church's original marble templon survives.
The church is most notable for its frescoes, contemporary with the church's construction, which cover almost the entire interior surface. The frescoes are an example of the Thessalonican school at the height of the 'Palaiologan Renaissance', and their creator may be the same who decorated the Hilandar monastery in Mount Athos in 1314. The church has been linked to the Serbian king Stephen Uroš II Milutin (r. 1282–1321), who is known to have sponsored churches in the city, on account of the depiction in the main aisle of St George Gorgos, the Serbian ruler's patron saint, and of St. Clemens of Ohrid, a favourite motif of the Serbian churches.
The monastery continued functioning throughout the Ottoman period. The frescoes were uncovered in 1957–1960 during restoration works.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.