Siege of Thessalonica (617)

Siege of Thessalonica
Part of the Avar–Byzantine Wars
Map of the northern Balkans in Late Antiquity
Date 617 or 618 Location Thessalonica Result Byzantine victory
Belligerents
Avars Sclaveni	Byzantine Empire

The siege of Thessalonica in 617 or 618 was an unsuccessful siege of the city of Thessalonica, the major Byzantine stronghold in the region, by the Avars and the Slavic tribes (Sclaveni) who had settled in the city's vicinity. The attack was the last and best-organized attempt by the Avars to take the city. It lasted 33 days and involved the use of siege engines, but in the end failed. The main source for these events are the Miracles of Saint Demetrius, named after Thessalonica's patron saint, Saint Demetrius.