6 dated entries naming Portus, drawn from 6 separate years between 42 CE and 891 CE. Nothing here is written by us: each line is the sentence a Wikipedia year article used, and the link beside it opens the exact revision.
474June 24 – Julius Nepos arrives at Portus, and marches on Ravenna. He forces Glycerius to abdicate the throne, and proclaims himself emperor of the Western Roman Empire.source
6th century
537April – The Goths capture the Portus Claudii at Ostia; the harbor is left unguarded by the Romans. Belisarius is forced to unload his supplies at Antium; he sends urgent messages for reinforcements to Constantinople.source
9th century
891September 14 – Pope Stephen V dies after a 6-year reign. He is succeeded by Formosus, former cardinal bishop of Portus, as the 111th pope of the Catholic Church.source