It became an episcopal see as part of the Diocese of Rome as early as the 3rd century AD. The episcopal church sponsored by Constantine the Great is located in the south-east of the city.Feist, Sabine; et al. (2023). "Die konstantinische Bischofskirche von Ostia. Vorbericht zur ersten Grabungskampagne 2023" [The Constantinian episcopal church of Ostia. Preliminary report on the first excavation campaign in 2023]. Kölner und Bonner Archaeologica 13, pp. 163–181. The city was mentioned by St Augustine when he passed there in the late 4th century. On their way back to Africa after Augustine's conversion to Christianity, Augustine's mother, Saint Monica, died in 387 in Ostia. The church (titulus) of Santa Aurea in Ostia was built on her burial site.
It became an episcopal see as part of the Diocese of Rome as early as the 3rd century AD. The episcopal church sponsored by Constantine the Great is located in the south-east of the city.Feist, Sabine; et al. (2023). "Die konstantinische Bischofskirche von Ostia. Vorbericht zur ersten Grabungskampagne 2023" [The Constantinian episcopal church of Ostia. Preliminary report on the first excavation campaign in 2023] Kölner und Bonner Archaeologica 13, pp. 163–181. The city was mentioned by St Augustine when he passed there in the late 4th century. On their way back to Africa after Augustine's conversion to Christianity, Augustin.e's mother, Saint Monica, died in 387 in Ostia. The church (titulus) of Santa Aurea in Ostia was built on her burial site.