Beginning in the sixth century BC, colonies of Ancient Greece, Ancient Rome, and the Byzantine Empire, such as Tyras, Olbia, and Chersonesus, were founded on the northeastern shore of the Black Sea. These colonies thrived well into the sixth century AD. The Goths stayed in the area, but came under the sway of the Huns from the 370s AD. In the seventh century AD, the territory that is now eastern Ukraine was the centre of Old Great Bulgaria. At the end of the century, the majority of Bulgar tribes migrated in different directions, and the Khazars took over much of the land.