's
colonial French coat of arms, showing its conflation by the French with the actual remains of ancient Portus Magnus to its southwest at present-day
Bethioua The city is located in a ruins of the ancient
Phoenicians of
Carthage and stood on a hill overlooking the ancient port. The city was named Portus Magnus after coming the Romans. The inhabitants were mostly Roman citizens, whose main exports were grain and salt. The settlement covered approximately , paved or leveled by landfills. In present Bethioua, there remain some walls and buildings, rainwater
cisterns, bits of Roman streets, and a small forum (). Off one side of the forum was a small building with marble countertops and a statue. Behind this was a temple of unknown dedication and, about west of the forum, there was another very large temple dedicated to
Venus. The colonnades () and spa near some of the Roman villas probably constituted a palatial resort of the 3rd century. During
their invasion of North Africa, the
Vandals destroyed Portus Magnus in AD 429 or 430. There is some evidence of
Byzantine Christian worship, showing some port activity continued after the area's 6th-century
Byzantine reconquest, during which it was involved in
repeated wars against local
Berber kingdoms. The settlement was fully abandoned after the
Islamic conquest of North Africa in the 7th century, the location of "Arzao" noted by
El Bekri as only bearing the remains of an abandoned Roman port . The
Almohads refounded the city and reopened the port in 1162 under the name
Bethioua. The French later conflated its history with their own larger nearby settlement at
Arzew. ==See also==