Not far from the citadel walls stands the patriarchal, stauropegial Blatadon Monastery, a Byzantine foundation which still functions today and one of the last, fine works of Byzantine art in Thessaloniki. It was founded between 1351 and 1371 by a monk named Dorotheos Blates, who was elected Metropolitan of Thessaloniki in 1371. He and his brother Markos had been disciples of Gregory Palamas (Metropolitan of Thessaloniki 1347-59); they supported Hesychasm and played a part in the reorganisation of the city after the collapse of the Zealots' short-lived regime (1342-9).
Originally dedicated to Christ Pantokrator, the monastery now honours the Transfiguration. All that survives of the Byzantine complex is the katholikon. The other buildings in the precinct are twentieth-century additions (the abbot's residence, the sacristy, the chapel of the Dormition of the Virgin, the Patriarchal Institute for Patristic Studies). The katholikon was built on the site of an earlier, probably mid-Byzantine, church as a variation on the cross-in-square with an ambulatory terminating in two chapels at the east end. The naos and the sanctuary, the south chapel (dedicated to St Peter and St Paul], and most of the south ambulatory belong to the original phase. The rest of the ambulatory was added in 1801, while the neoclassical propylon and the open portico on the south side were added in 1907.
The interior is decorated with wall paintings which date to 1360-80, after the death and canonisation of Gregory Palamas (1359]: the Pantokrator, angels, and prophets in the dome, fragmentary Great Feasts in the arches in the naos, and ascetics and monks on the walls. The Baptism and the Three Hebrews survive in good condition in the two niches in the narthex, accompanied by warrior saints and fragments of Christ's miracles elsewhere in the narthex. Two representations of Gregory Palamas, one on the right-hand wall of the entrance from the narthex to the naos and the other in the south chapel with the great theologians of the Church, confirm the monastery's close connection with the Hesychast movement.
After Thessaloniki fell to the Ottomans in 1430, the monastery survived and enjoyed privileged status, both as a patriarchal foundation and because it controlled the city's water supply. Its Turkish name, Chaush Manastir, connects it with Chaush Bey, who built the tower which bears his name in the Heptapyrgion Fortress in 1431. The frescoes have been badly damaged by hammer blows, indicating that the church spent some unspecified period of time in Ottoman hands. But this was probably a brief episode, as the alterations and additions, the carved seventeenth-century chancel screen, and the collection of icons in the sacristy all attest that it was in constant use.
After the earthquake of 1978, restoration and conservation work was carried out, in the course of which unknown frescoes were discovered that add to our knowledge of monumental painting in the final phase of the Palaiologan era.
 

Blatadon Monastery (Moni Vlatadon)
Blatadon Monastery (Moni Vlatadon)
Blatadon Monastery (Moni Vlatadon)
Blatadon Monastery (Moni Vlatadon)
Blatadon Monastery (Moni Vlatadon)