Heracleion (Greek: Ἡράκλειον), also known as Thonis (Θῶνις), was an ancient Egyptian city located near the Canopic Mouth of the Nile, about 32km northeast of Alexandria. Its ruins are located in Abu Qir Bay, currently 2.5 km off the coast, under 10 m (30 ft) of water. Its legendary beginnings go back to as early as the 12th century BC, and it is mentioned by ancient Greek historians. Its importance grew particularly during the waning days of the Pharaohs. In the Late Period, it was Egypt’s main port for international trade and collection of taxes.
Heracleion was originally built on some adjoining islands in the Nile Delta, and was intersected by canals. It had a number of harbors and anchorages and was the sister city of Naucratis until it was superseded by Alexandria.
The stelae of Ptolemy VIII from the temple of Heracleion
Heracleion was said by Herodotus to have been visited by Paris and Helen of Troy. It was believed[by whom?] that Paris and Helen were stranded there on their flight from the jealous Menelaus, before the Trojan war began or that Menelaus and Helen had stayed there, accommodated by the noble Egyptian Thon and Polydamna. Also, it was believed that Heracles himself had visited the city, resulting in the Greeks calling it by the Greek name Heracleion rather than its original Egyptian name Thonis
The city was mentioned by the ancient historians Diodorus (1.19.4) and Strabo (17.1.16). Herodotus was told that Thonis was the warden of the Canopic mouth of the Nile: Thonis arrested Alexander (Paris), the son of Priam, because Alexander had abducted Helen of Troy and taken much wealth.
Heracleion is also mentioned in the twin steles of the Decree of Nectanebo I (the first of which is known as the ‘Stele of Naukratis’), which specify that one tenth of the taxes on imports passing through the town of Thonis/Herakleion were to be given to the sanctuary of Neith of Sais. The city is also mentioned in the Decree of Canopus honoring Pharaoh Ptolemy III.
The city of Heracleion was also the site of the celebration of the ‘mysteries of Osiris’ each year during the month of Khoiak. The god in his ceremonial boat was brought in procession from the temple of Amun in that city to his shrine in Canopus.