Mahdia (المهدية ) is a Tunisian coastal city with 62,189 inhabitants, south of Monastir and southeast of Sousse.
Mahdia is a provincial centre north of Sfax. It is important for the associated fish-processing industry, as well as weaving. It is the capital of Mahdia Governorate.
The old part of Mahdia corresponds to the Roman city called Aphrodisium and, later, called Africa (a name perhaps derived from the older name), or Cape Africa. The Catholic Church's list of titular sees includes a no longer residential bishopric called Africa and, since there is no record of an episcopal see in Roman times called by either of these names (nor by that of Alipota, another Roman town that Charles Tissot suggested tentatively might be represented by present-day Mehdia), it is supposed that the episcopal see of Africa was established when the city was held by the Kingdom of Sicily, as a part of the Kingdom of Africa (1147–1160) and when Pope Eugene III consecrated a bishop for it in 1148. An inventory of movable property of the church of Africa (inventarium thesauri Africani) exists in an archive of the Cappella Palatina of Palermo in Sicily. Robert Favreau identified Mahdia instead with ancient Ruspae or Ruspe, which is more commonly taken to have been at Henchir Sbia (or just Sbia), north of Mahdia, or at the ruins known as Ksour Siad. The most illustrious bishop of this see was Fulgentius of Ruspe. The Catholic Church's list of titular sees, which identifies the see of Africa as Mahdia, identifies Ruspe/Ruspae as Henchir Sbia.
The Mahdia shipwreck – a sunken ship found off Mahdia's shore, containing Greek art treasures – is dated to about 80 BC, the early part of Roman rule in this region.
Muslim Mahdia was founded by the Fatimids under the Caliph Abdallah al-Mahdi and made the capital of Ifriqiya. As the then-newly-created Fatimid Caliphate was a Shi'a regime supported by a Berber Kutama military, the caliph may have been motivated to move his capital here so as to put some distance between his power base and the predominantly Sunni city of Kairouan (the traditional capital of Ifriqiya up to that point).