The Cantabri were a Celtic tribe which inhabited the northern coastal region of the Iberian Peninsula. The Cantabri migrated to Cantabria in the 4th century BC, and they were regarded by the Romans as savage and untamable mountaineers. Cantabrian mercenaries fought for Carthage during the Punic Wars, and the Cantabri first submitted to the Roman Republic in 195 BC. However, the Cantabri continued to fiercely resist Roman rule, and they failed in their attempts to support the Aquitani against the Romans during the Gallic Wars of the 50s BC. In 19 BC, the Cantabri were incorporated into the Roman province of Hispania Tarraconensis, and they were never fully Romanized and never fully lost their warrior skills. The Cantabri re-emerged in the late 4th century AD, and they were violently crushed by the Visigoths in the late 6th century AD after becoming Christianized. They became fully Latinized in their language and culture after the Muslim invasion of Spain in the 8th century AD.