Mauretania is a region of Africa, separated from Spain by the straits of Gibraltar, and from Numidia by the river Ampsaga. It is now Morocco. Julius Caesar vanquished its king, Juba, and reduced the country to a Roman province. Augustus later exchanged it with Juba, the son, for Numidia. The region remained under the Romans until about 441 A.D., when Genseric, King of the Vandals, gained possession of it. Valentinian fought for it for three years, with various success; at length, peace was established and they divided Northern Africa between them. At the death of Valentinian, Genseric not only recovered all which he had ceded but overthrew the Empire of the West. Justinian reconquered this territory ninety-five years after the Vandals had permanently occupied it.