Krum, khan of the Bulgarian Khanate

Krum, often referred to as Krum the Fearsome was the Khan of Bulgaria from sometime between 796 and 803 until his death in 814. During his reign the Bulgarian territory doubled in size, spreading from the middle Danube to the Dnieper and from Odrin to the Tatra Mountains. His able and energetic rule brought law and order to Bulgaria and developed the rudiments of state organization.

The First Bulgarian Empire was a medieval state that existed in Southeastern Europe between the 7th and 11th centuries AD. It was founded in 680–681 after part of the Bulgars, led by Asparuh, moved south to the northeastern Balkans. There they secured Byzantine recognition of their right to settle south of the Danube by defeating – possibly with the help of local South Slavic tribes – the Byzantine army led by Constantine IV. During the 9th and 10th century, Bulgaria at the height of its power spread from the Danube Bend to the Black Sea and from the Dnieper River to the Adriatic Sea and became an important power in the region competing with the Byzantine Empire.