"At the mouth of the Tiber River, Ostia was Rome's seaport. Ostia means mouth in Latin. This coin was issued to commemorate the completion of an artificial harbor at Ostia, begun under Claudius in 42 A.D. and completed under Nero in 64 A.D.
The earliest known post-diaspora house-synagogue was at Ostia. In 387, St. Augustine stayed in Ostia with his mother, who died there.
Ostia began to decline in the Severan period. By the Constantine Dynasty, Portus was the main port for Rome. Earthquake damage at Ostia was left uncleared. At the end of the fifth century the aqueduct stopped functioning. In 537 with the area under attack from the Goths, the remaining inhabitants retreated to the theater, which they turned into a little fortress. Early in the ninth century Ostia was captured by the Saracens and abandoned.
Ostian marble was reused in the cathedrals of Pisa, Florence, Amalfi and Orvieto. The Leaning Tower of Pisa was entirely built of material from Ostia. Despite all this, Ostia today is known for its well preserved ruins and magnificent frescos.