ARMORICA (AREmoRICA), the Roman name, derived from two Celtic words meaning the "seaside" (or, on, and mor, sea), for the land of the Armorici, roughly the peninsula of Brittany. At the time of Caesar's advance on Gaul there were five princi pal tribes in Armorica, among whom were the Veneti (q.v.), who were entirely destroyed by Caesar. Under the empire it formed part of the province of Gallia Lugudunensis. It contained hardly any towns and was perhaps less Romanized than the rest of Gaul. In and after the later part of the 5th century it received many Celtic immigrants from the British Isles, fleeing (it is said) from the Saxons; and the Celtic dialect which the Bretons still speak is thought to owe its origin to these immigrants. (See BRIT TANY.)