Alexandria was among the largest and most magnificent cities in antiquity. Founded by Alexander the Great in 331 BC, its architecture and culture even overshadowed those of the city of Rome. Palaces and temples dominated the skyline. The beauty of this political, religious, cultural and scientific capital aroused the admiration of visitors such as the Greek geographer Strabo. The population had already passed the 100,000 mark shortly after Alexandria’s founding. The city’s 130 metres high Pharos lighthouse represented one of the Seven Wonders of the Ancient World. Alexandria was also famous for its huge library with about half a million roles of papyrus. Parts of the city’s royal quarter with its temples, palaces, royal gardens and harbour structures were situated in the eastern harbour, called the Portus Magnus. Here, on the Island of Antirhodos and the Poseidium Peninsula, Julius Caesar, Marc Anthony and the famous Cleopatra used to stay.
Due to a combination of natural phenomena, including a series of earthquakes and tidal waves, the Portus Magnus and parts of the city’s ancient coastline sank beneath the sea. For more than 1,200 years temples, buildings, palaces, statues, ceramics, coins, jewellery and every day objects lay untouched on the seabed covered by thick layers of sand and sediment.
In 1992, the IEASM began underwater explorations under the supervision of Franck Goddio and in cooperation with the Egyptian Supreme Council of Antiquities. The zone of research covers the current eastern port, which measures approximately 400 hectares in area. After an extensive programme of electronic surveys to create an accurate map of the harbour floor, archaeological remains buried under the sediment were located by selective mechanical soundings or through the use of electronic detection instruments such as nuclear magnetic resonance (NMR) magnetometers.
The archaeological campaigns have made it possible to develop, for the first time, a complete panorama of the famous Portus Magnus. The topography obtained is very different from what had been previously imagined from ancient texts. We now know how the eastern port of Alexandria looked during the Ptolemaic and Roman Periods.