The area that is today the Czech Republic was originally inhabited by Celts around the 4th century BC. The Celtic Boii tribe gave the country its Latin name—Boiohaemum (Bohemia)—but was driven out by Germanic tribes. Slav tribes migrated to central Europe during the period known as the Migration of Peoples and were well established by the 6th century. The first half of the 7th century saw allied Slavonic tribes defending their territory from the Avar Empire in the Hungarian lowlands and from Frank attackers to the West.