Krum was a Khan of Bulgaria from 808 to 814. By defeating the Avar Thaganate, he expanded his territory to cover the lands between the Danube and the Carpathians. Before the end of 809, the Khan's soldiers had defeated the Byzantine army and Serdika, which was later to become Bulgaria's capital, was captured.
In 811 the Byzantine Empire army captured Pliska, the capital of Bulgaria. After the palace was destroyed Krum sued for peace offering Nicephorus I anything he wanted. The Byzantine Emperor refused the proposal. In July Krum got his revenge, laying siege on the Byzantine army, killing the Emperor. It is said that Krum had the Emperor's skull lined with silver, using it as a drinking cup. Leading his army south, Krum seized Byzantine towns and strongholds.
Krum's sudden death on April 13, 814 put an end to his plan to enter the Emperor's palace as a conqueror. He also made other important contributions. Bulgaria's first written laws. Applicable to all Bulgarians, his laws ensured subsistence to beggars and state protection to the poor. Through his laws he became known as a magnanimous ruler, bringing Slavs and Bulgars into a centralized state.