Siege of Thessalonica

The Ottoman Sultan Murad II decided to capture the city of Thessalonica (the second most important city of what was left of the Byzantine Empire) in order to punish the ruling Byzantine Palaiologoi dynasty for their attempts at inciting rebellion within the Ottoman ranks. The city capitulated in 1387 to Hayreddin Pasha but it was taken back during the Ottoman civil war (1402-1413). 
Murad II laid siege to the harbor of Thessalonica in 1422. In 1423, the Byzantine local ruler Andronikos Palaiologos handed the city to the Republic of Venice, which assumed the burden of its defense. Andronikos’ decision did not have the full support of the population, and was opposed by the church, which mistrusted the "Latins" The handing over of Thessalonica contributed to the outbreak of the first in a series of wars between Venice and the Ottoman Empire. Sultan Murad II declared war on his former ally and attacked Venetian possessions in the Adriatic and southern Greece. 
In another version of this story, the Byzantines sold the city to the Venetians, but that was probably just Turkish propaganda. As a matter of fact, the Byzantines were trying to hand over even Constantinople to the Venetians, to save it from the Turks, but the Venetians declined.

The Venetian forces came to Thessalonica in 1423. The Venetians had not realized how expensive the defense of the city would be. Nonetheless, the city held out despite severe hunger. Murad II had been engaged during that period in numerous fights elsewhere against Venetians and others, while maintaining the naval blockade of the city; when finally Murad had subdued all his enemies, he sent a large army to Macedonia and the city was captured. 
Thessalonica was brutally sacked and pillaged; roughly one-fifth of the city's population was enslaved. Many of its inhabitants escaped to the West. However, the change of sovereignty from the Byzantine Empire to the Ottoman one did not affect the city's prestige as a major imperial city and trading hub.

Venetians & Byzantines	Ottoman Turks
Commander	Commander
Andronicos Palaiologos (until	Unknown
Forces	Forces
Unknown	Unknown
Casualties	Casualties
2000-7000 citizens enslaved	—

The Battles of History