Editing Ostia Antica (section)

===Late-Roman and sub-Roman Ostia===
[[File:La maison de Diane (Ostia Antica) (5900777253).jpg|thumb|Via di Diana]]

Although it used to be thought that the city entered a period of slow decline after [[Constantine the Great]] made Portus a municipality, indicated by some apartment blocks being replaced by houses of the rich, recent excavations show that the town continued to thrive.<ref>''Ostia in Late Antiquity'', [[Douglas Boin]], 2013, Cambridge University, p. 65 {{ISBN|978-1-316-60153-2}}</ref> Numerous baths are recorded as still operating in the 4th and 5th centuries with major repairs of the city's Neptune Baths in the 370s. During the 4th century, the city spilled over the southern walls to the sea south of Regions III and IV.

The poet [[Rutilius Namatianus]] reported the lack of maintenance of the city ports in 414 AD.<ref name="RutiliusNamatianus">{{cite web|title=RUTILIUS NAMATIANUS|url=http://www.ostia-antica.org/~atexts/rutilius.htm|website=www.ostia-antica.org|access-date=1 September 2017}}</ref>  This view has been challenged by Boin who states Namatianus' verse is a literary construct and inconsistent with the archaeological record.<ref>''Ostia in Late Antiquity'', Boin, 2013, pp. 22, 25. The poet was lamenting the lost greatness of Rome after the sack of 410.</ref>

Prosperity in the 5th century is indicated by repairs on baths (26 remained in operation during the 4th century), public buildings, church construction, street repaving, residential and business expansion beyond the perimeter of the south wall (the presence of a small harbour, the Porta Marina on the sea, is attested). A huge 4th century villa east of the Maritime baths was built. The river port on the western edge of the town was expanded with the ''navalia'', a squarish basin built in from the river. A warehouse on the east side and, behind it, a large bath complex were built.<ref>''Ostia in Late Antiquity'', Boin, 2013, pp. 21, 24, 52-53, 56, 57-65, 165, 231-236</ref>

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.{{sfn|Heinzelmann|2020|p=15–120}}<ref>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.</ref> The city was mentioned by [[Augustine of Hippo|St Augustine]] when he passed there in the late 4th century.<ref name="StAugustineOstia">{{cite web|title=St. Augustine at Ostia|url=http://celt.ucc.ie/published/E880000-004/text001.html|website=celt.ucc.ie|access-date=1 September 2017}}</ref> On their way back to Africa after Augustine's conversion to Christianity, Augustine's mother, [[Saint Monica]], died in 387 in Ostia.<ref>{{cite book|last = Augustine|first = E.|date = 1977|title = Confessions|location = London|publisher = Penguin|isbn = 014044114X|pages = [https://archive.org/details/confessions00augu/page/196 196]–197|url-access = registration|url = https://archive.org/details/confessions00augu}}</ref> The church (''[[titulus (Roman Catholic)|titulus]]'') of [[Santa Aurea]] in Ostia was built on her burial site.

After the [[fall of the Western Roman Empire]] in 476, Ostia fell slowly into decay as the population of Rome, 700–800,000 in AD 400 contracted to 200,000 or less in 500 AD. A naval battle, the [[Battle of Ostia]], was fought there in 849 between [[Christians]] and [[Saracens]]; the remaining inhabitants moved to [[Gregoriopolis]] a short distance away.<ref name="EncyclopediaBritannicaOstia" />