The Celts were a diverse group of tribal societies in Iron Age Europe. Proto-Celtic culture formed in the Early Iron Age in Central Europe (Hallstatt period, named for the site in present-day Austria). By the later Iron Age (La Tène period), Celts had expanded over wide range of lands: as far west as Ireland and the Iberian Peninsula, as far east as Galatia (central Anatolia), and as far north as Scotland. By the early centuries AD, following the expansion of the Roman Empire and the Great Migrations of Germanic peoples, Celtic culture had become