The Battle of Versinikia is fought in 813 between the Byzantine Empire and the Bulgarian Empire, near the city of Adrianople (Edirne) in contemporary Turkey.Despite being vastly outnumbered, the Bulgarians are victorious, resulting in the dethroning of Michael I Rangabe (811-813) by Leo V the Armenian.

The battle is a major success and further strengthensthe Bulgarian position after their decisive victory over Nikephoros I two years earlier.

In fact, after the battle they de facto take control of the whole of Eastern Thrace (until the Treaty of 815) with the exception of a few castles that remain in Byzantine control.

For the first time in the Bulgarian history, the way to Constantinople is opened.

Unfortunately for them, the great Khan Krum dies in the height of the preparation for the final siege of the Byzantine capital on April 13, 814.