Hispania was the Roman name for the Iberian Peninsula. Under the Roman Republic, it was divided into two provinces: Hispania Citerior and Hispania Ulterior. During the Roman Empire, under the Principate, Hispania Ulterior was subdivided into Baetica and Lusitania, while Hispania Citerior was reorganized as Hispania Tarraconensis.
Beginning with Diocletian’s Tetrarchy (AD 293), the territory of Tarraconensis was further divided to create the provinces of Carthaginensis and Gallaecia (also called Callaecia, the origin of the name of modern Galicia). All the Hispanic provinces on the mainland, together with the Balearic Islands and the North African province of Mauretania Tingitana, were later organized into the Diocesis Hispaniarum, governed by a vicarius.
