Alexandria Under the Ptolemies: The Library, the Lighthouse, the Legend

For 300 years, Alexandria was the most important city in the Mediterranean. It had the ancient world’s largest library, its most famous lighthouse, its most ethnically mixed population, and — arguably — its highest concentration of working scientists and scholars. It was where Euclid taught geometry, Eratosthenes calculated the circumference of the Earth to within 2%, and the Old Testament was first translated into Greek.

Today most of ancient Alexandria is either under the modern city or under the sea. But enough survives that a two-day visit is genuinely worth doing on any Egypt trip. Start with our Egypt travel guide, and see the wider context in the complete history of ancient Egypt.

Alexander’s city

Alexander the Great arrived in Egypt in 332 BC, at the age of 24, fresh from breaking the Persian Empire in Syria. Egypt welcomed him as a liberator — the Persians had ruled Egypt for the previous 200 years with a heavy hand, and Alexander’s arrival was, in local terms, a gift from Amun.

Alexander was crowned pharaoh at Memphis, made a pilgrimage to the oracle of Amun at the desert oasis of Siwa (where the priests confirmed he was the son of god), and then, on the way back to the coast, stopped at a small fishing village called Rhakotis. Something about the geography — the natural harbour, the fresh water lake behind it, the shelter provided by the island of Pharos offshore — made him stop.

He laid out the plan of a new city with barley flour (having run out of chalk) and named it after himself. Then he left, marched east, and died 10 years later in Babylon at the age of 32. He never saw the city built.

The Ptolemies take over

When Alexander died, his empire was carved up among his generals. Egypt fell to a shrewd Macedonian officer named Ptolemy, who founded a dynasty that ruled from Alexandria for the next 275 years — until Cleopatra VII lost the country to Rome in 30 BC (see our post on Cleopatra).

The Ptolemies were absentee Greeks running an Egyptian country, and they made a strategic decision early: keep Alexandria as a Greek city on Egyptian soil, and use its wealth to sponsor culture on a scale no ruler had ever attempted. Immigration was welcomed — the city ended up with the largest Jewish population outside Judea, a substantial Egyptian quarter, plus Greeks, Romans, Syrians, Nubians, Persians and Indians. In its prime, Alexandria may have held 500,000 people, making it the largest city in the world outside China.

The Library of Alexandria

The Library was founded by Ptolemy I around 295 BC and expanded aggressively by his son Ptolemy II. The strategy was direct and slightly aggressive: every ship that docked in Alexandria was searched for books, the books were confiscated, and copies were made in the Library’s scriptorium. The originals stayed. The copies were returned to the owners.

At its peak the Library may have held 400,000 to 700,000 scrolls (estimates vary wildly). Alongside it sat the Musaeum — a research institution funded directly by the state, where scholars lived on royal stipends, ate together in a communal dining hall, and were expected to produce work. It was effectively the world’s first university and research institute. Scholars associated with it included:

• Euclid — wrote the Elements, the geometry textbook still in partial use today
• Eratosthenes — calculated the Earth’s circumference to about 39,000 km (real value: 40,075 km) using shadows in two Egyptian cities
• Archimedes — studied there, though most of his work was later done back home in Syracuse
• Aristarchus — proposed a heliocentric model of the solar system 1,700 years before Copernicus
• Herophilus — the first Western anatomist, first person to distinguish arteries from veins
• Ctesibius — inventor of the pipe organ, the water clock and pneumatic devices

The library was not destroyed in a single dramatic event. It declined over several centuries. Julius Caesar accidentally burned a warehouse of scrolls in 48 BC while defending himself in the harbour. The city’s decline under later Roman emperors, occasional riots, and the closure of pagan institutions by Christian emperors like Theodosius I in the 4th century AD all took their toll. By the time the Arab general Amr ibn al-As arrived in 641 AD, the great collection was probably long gone.

The Pharos Lighthouse

The lighthouse was built on the small island of Pharos at the mouth of the harbour, around 280 BC, under Ptolemy II. It was one of the tallest buildings in the ancient world, estimated at 100-140 metres — taller than any structure in Europe until the 19th century.

The design was three tiers: a square base, an octagonal middle, a cylindrical top, with a fire (and possibly a bronze mirror to project the light) at the summit. Roman-era sources say the light was visible 50 km out at sea. It gave its name to lighthouses in most Mediterranean languages — French phare, Italian faro, Spanish faro, Greek pharos.

The lighthouse survived until a series of earthquakes in the 10th, 12th and 14th centuries brought it down. In 1477 the Mamluk sultan Qaitbey built a fortress on its foundations using the fallen lighthouse blocks. Fort Qaitbey still stands today, easily visitable, and marine archaeologists working in the harbour since the 1990s have located substantial parts of the collapsed lighthouse on the seabed nearby.

What Alexandria became

The city was more than its two headline monuments. The Serapeum — a temple to the composite Greek-Egyptian god Serapis — was one of the largest religious buildings in the ancient world. The Ptolemaic royal quarter had palaces along the shoreline. There were Greek gymnasia, Egyptian temples, Jewish synagogues, and one of the earliest Christian communities in the world.

The intellectual legacy is arguably the deepest. The Septuagint — the Greek translation of the Hebrew Bible — was made in Alexandria around 250 BC, and became the standard version used by early Christians. Alexandrian scholars established the basic tools of Western literary criticism, including the concepts of edition, canon, and commentary. Modern biology and medicine trace direct lineages to Herophilus and Erasistratus.

What survives today

• Fort Qaitbey: stands on the Pharos lighthouse’s foundations at the tip of the eastern harbour
• Roman theatre + Villa of the Birds (Kom El-Dikka): excavated Roman-era complex in the city centre with a preserved amphitheatre and beautiful mosaics
• Catacombs of Kom El-Shoqafa: a huge Roman-Egyptian tomb complex with striking hybrid iconography — Anubis in Roman armour, sphinxes with human faces
• Pompey’s Pillar: a 26-metre granite column, all that remains above ground of the great Serapeum
• Bibliotheca Alexandrina: the modern library opened in 2002 as a spiritual successor to the ancient one, with excellent exhibits on the Ptolemaic city
• Alexandria National Museum: compact and well-curated, covers Pharaonic, Ptolemaic, Roman and Coptic phases
• Underwater archaeology tours: occasional diving tours over the sunken royal quarter, sphinxes and lighthouse blocks — check operators in advance

Alexandria is easily done as a two-day trip from Cairo (2.5 hours by high-speed train each way). See Egypt travel guide and best time to visit Egypt.

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