Thessaloniki, the second largest city for most of the existence of the Eastern Roman (Byzantine) Empire, fell to the Ottoman Empire on March 29, 1430 after an eight siege led by Sultan Murad II.
The city remained in Ottoman hands for the next five centuries, until it finally became part of the Kingdom of Greece in 1912 after the Greek Army liberated the city in the First Balkan War.
Thessaloniki had already been under Ottoman control from 1387 to 1403 before it returned to Byzantine rule in the aftermath of the Battle of Ankara.
In 1422, after the Byzantines supported Mustafa Çelebi as a rival pretender against him, Murad attacked Thessaloniki.
Unable to provide manpower or resources for the city’s defense, its ruler, Andronikos Palaiologos, handed it over to the Republic of Venice in September 1423.
The Venetians attempted to persuade the Sultan to recognise their possession, but failed as Murad considered the city his by right and the Venetians to be interlopers.
This impasse led to an Ottoman blockade of Thessaloniki, which occasionally flared up with direct attacks on the city.
At the same time, the conflict was mostly fought as a series of raids by both sides against the other’s territories in the Balkans and the Aegean Islands.
The Venetians repeatedly tried to apply pressure by blocking the passage of the Dardanelles at Gallipoli, with little success.
The blockade quickly reduced the inhabitants to near starvation, and led many to flee the city.
The restrictions placed on them by the siege, the inability of Venice to properly supply and guard the city, the violations of their customary rights, and rampant profiteering by Venetian officials led to the formation of a pro-surrender party within the city, which gained strength among the inhabitants.
The city’s metropolitan bishop, Symeon, encouraged his flock to resist.
However, by 1426, with Venice’s inability to secure peace on its own terms evident, a majority of the local population had come to prefer a surrender to avoid the pillage that would accompany a forcible conquest.
Venice’s efforts to find allies against the Ottomans also failed: the other regional potentates either pursued their own course, were themselves antagonistic to the Venetians, or were defeated by the Ottomans.
After years of inconclusive exchanges, the two sides prepared for a final confrontation in 1429.
In March, Venice formally declared war on the Ottomans, but even then the conservative mercantile aristocracy running the Republic were uninterested in raising an army sufficient to protect Thessaloniki, let alone to force the Sultan to seek terms.
In early 1430, Murad was able to concentrate his forces against Thessaloniki, taking it by storm on 29 March 1430.
The privations of the siege and the subsequent sack reduced the city to a shadow of its former self, from perhaps as many as 40,000 inhabitants to c. 2,000, and necessitated large-scale resettlement in the following years.
Venice concluded a peace treaty with the Sultan in July, recognising the new status quo. Over the next few decades, the antagonism between Venice and the Ottomans morphed into a rivalry over control of Albania.
Following the capture of Thessaloniki, the Ottomans went on to extend their rule over western Greece. A few months after the fall of the city Ioannina surrendered to Hamza Bey and Carlo II Tocco accepted Ottoman suzerainty over the southern remnant of the Despotate of Epirus around Arta. Venice moved to place Tocco’s island possessions of Zante, Cephalonia, and Leucas under her protection.
As a result, for the next half-century, until the end of the First Ottoman–Venetian War in 1479, the main arena of confrontation between Venice and the Ottomans was to be Albania, an area of vital importance to both powers, as from there the Ottomans could threaten Italy herself.
Thessaloniki remained in Ottoman hands until October 1912, when it was captured by the Kingdom of Greece during the First Balkan War. Its remaining Muslim population left the city during the Greco-Turkish population exchange in 1923.