Siege of Constantinople, 626

The Avar Khaganate was a state ruled by the Avars, who appeared in Central Europe in the sixth century. In 567, the Avars conquered Pannonia, encompassing present-day Hungary, Austria and parts of the former Yugoslavia. On this conquered territory they established their powerful state, called a khaganate. The Avar Khaganate quickly became a major regional power, known for its military skills and conquests. It emerged as a durable military force that frequently captured and subjugated neighbouring empires and tribes.

In the summer of 626, they conducted a ten-day siege of Constantinople. Avars, Bulgars and Slavs all participated. During the siege, the Slavs were responsible for the attack from the sea, using boats carrying both lightly and heavily armed warriors.

During the siege, the Slavs were defeated. This angered the khagan, who ordered all the Slavs to be killed. His action destroyed any prospect of good relations with the Slavic tribes thereafter.