Southern Germany reputedly is the area from which various iron-age pagan tribes, known to be tall, speaking Celtic dialects, and wearing tartan plaids, dispersed throughout western Europe, beginning about 1000 B.C. Many of those among them who did not have natural blond hair would artificially change their hair color to blond. Celtic tribes migrated over the Alps and settled in the Po Valley of northern Italy about the 5th century B.C. They conquered Rome in 390 B.C. They moved into France and Spain, and eventually into Ireland and Great Britain. Today there are still place-names showing their presence (e.g., Tubingen, Gernmany derives from a Celtic word). The Teutonic language replaced the Celtic language in Southwestern Germany about 100 B.C. Caesar called the Celtics barbarian, but in actuality, they were among the most advanced craftsmen at metalwork. Some would say their metalwork has never been surpassed. They attained a high reputation for the eloquence of their poets, storytellers, bards and kings. Unfortunately, nothing in writing was left. Their Kings prided themselves on their illustrious descent from warrior-kings.