Siege of Constantinople, 813

In July 811, Krum defeated the Byzantine army at the Varbitsa Pass and killed Emperor Nikephoros I. He then attacked Thrace, capturing fortresses including Anchialos, Provat and Beroe.

In 812, Krum sent envoys to Emperor Michael I Rangabe proposing peace, but the offer was rejected. Krum consequently captured Mesembria, seizing riches and 36 copper siphons for Greek fire. Leo V the Armenian became emperor in July 813. A week later, Krum arrived before Constantinople and began a siege. One of his peace conditions was permission to thrust his spear into the city's Golden Gate. At the meeting to conclude peace, however, he realised he had been ambushed when one of his envoys removed his hat without apparent reason.

Enraged, Krum devastated eastern Thrace, left his brother in charge of the siege of Adrianople and concentrated on Constantinople. Accounts state that during the ambush he offered sacrifices to Tangra, frightening Constantinople's inhabitants. In autumn and winter, he made extensive preparations for a renewed siege. His massive siege engines were so numerous and heavy that thousands of wagons, oxen and soldiers were allocated to transport them. In spring 914, when the siege was to resume with the new machines, Krum suddenly suffered a stroke and died.

Although he assembled a large army and siege equipment with numerous wagons and oxen, Krum died during preparations for the siege.