Sack of Thessalonica: Saracen raiders under Leo of Tripoli sack Thessaloniki, the Byzantine Empire's second-largest city, after a short siege, and plunder it for a week.

The sack of Thessalonica was the capture and subsequent sack of the Byzantine city of Thessalonica by the Abbasid Caliphate in the year 904, led by Leo of Tripoli, a privateer and Muslim convert.

Leo of Tripoli, known in Arabic as Rashīq al-Wardāmī, and Ghulām Zurāfa, was a Greek renegade and fleet commander for the Abbasid Caliphate in the early tenth century. He is most notable for his sack of Thessalonica, the Byzantine Empire's second city, in 904.

Thessaloniki is the second-largest city in Greece and the capital of the geographic region of Macedonia, the administrative region of Central Macedonia and the Decentralized Administration of Macedonia and Thrace. It is also known in Greek as i Symprotévousa, literally "the co-capital", a reference to its historical status as the "co-reigning" city of the Byzantine Empire alongside Constantinople.

The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived the events that caused the fall of the Western Roman Empire in the 5th century AD, it endured until the fall of Constantinople to the Ottoman Empire in 1453. The term 'Byzantine Empire' was coined only after its demise; its citizens used the term 'Roman Empire' and called themselves 'Romans'.