The Pharos of Alexandria
The Port That Needed a Light
Alexandria was not a naturally obvious harbour site. The Egyptian coast west of the Nile delta is a long, low shoreline without prominent headlands or natural deep-water inlets — navigators approaching from the open Mediterranean had little to guide them. Alexander the Great chose the site in 331 BCE for reasons that had more to do with strategic position and access to the Nile hinterland than with natural maritime advantage. What the site lacked, the engineers of his successors would have to provide: a harbour, a mole, a breakwater, and, eventually, a light.
The harbour was developed by the Ptolemaic dynasty that ruled Egypt after Alexander's death, with enormous investment in the engineering of the anchorage and the city around it. By the third century BCE, Alexandria was the pre-eminent commercial port of the eastern Mediterranean, handling the grain exports that fed much of the ancient world and the luxury trade that connected Egypt to Rome, Greece, and beyond. A port of that consequence needed to be identifiable from the sea, by day and by night, across the featureless stretch of water that separated it from Cyprus, Crete and the Aegean.
Building the Wonder
Construction of the Pharos began under Ptolemy I Soter and was completed, according to the most widely cited ancient sources, around 280 BCE during the reign of Ptolemy II Philadelphus. The architect's name has survived in an unusual way: the Greek Strabo records an inscription stating that a Cnidian architect named Sostratus of Cnidus erected the lighthouse 'for the safety of mariners,' though later writers suggested the inscription on the visible face gave Ptolemy credit and Sostratus's name was carved underneath, where the plaster overlay would eventually decay and reveal the true dedication. Whether this is architectural legend or historical fact cannot now be verified, but the story has been retold in every significant account since antiquity.
The structure was built on the eastern tip of the island of Pharos, which was connected to the mainland by a causeway — the Heptastadion — that divided the harbour into two basins. This position, at the extremity of the causeway island, gave maximum elevation and visibility without compromising the port approach. The tower was constructed in three stages: a square lower section, an octagonal middle section, and a cylindrical top, each diminishing in diameter and set slightly back from the one below, in the pattern that had already been used for the watchtowers of the Macedonian and Greek world. At the summit, an open fire burned in a stone brazier, visible at sea for, according to various ancient estimates, between 300 and 500 stadia — roughly 50 to 80 kilometres. These figures are almost certainly exaggerated, but a fire elevated to the height suggested by the ancient descriptions would have been visible in clear conditions for at least 35 to 40 kilometres.
The height of the structure is the most debated question in Pharos scholarship. Ancient authors give figures ranging from 100 to 140 metres; medieval Arab travellers who saw the partly ruined tower estimated between 70 and 100 metres. The most careful modern reconstructions, working from the Arab accounts and the site dimensions, tend toward a figure around 100 to 115 metres. If that range is correct, the Pharos was the tallest building in the world from its completion until the construction of the great medieval cathedrals.
The Light and the Mirror
The most intriguing detail in the ancient accounts of the Pharos is the description of an optical device at the summit that reflected the flame over greater distances. Several ancient and medieval writers refer to a concave metal mirror — polished bronze or silver — that focused the firelight into a beam. Some accounts are more specific, describing the ability to see ships far out to sea by means of the reflected light, functioning almost as a telescope.
The reflecting telescope did not exist in the ancient world in any usable form. What the mirror almost certainly did was what parabolic reflectors in early modern lighthouses did: concentrate the rearward-going light and redirect it forward, increasing the effective brightness in one direction at the cost of reduced output elsewhere. A large polished bronze concave reflector, properly positioned behind the flame, could have significantly increased the range of the light in the direction of the sea approaches. The principle is identical to that of the catoptric lighthouse optics developed in Europe in the eighteenth century, more than two thousand years later. Whether the Ptolemaic engineers understood the optics explicitly or arrived at the concave reflector by practical experimentation is not known.
The Pharos in the Arab Period
The Pharos survived, in progressively deteriorating condition, through the Roman period, the Byzantine era, and into the Islamic period. Arab travellers and geographers described it extensively from the seventh century onwards. Ibn Jubayr, who visited Alexandria in 1183, described a still-functional structure. Al-Idrisi, the twelfth-century geographer, gave measurements that scholars have used to reconstruct the upper portions of the tower. The damage was incremental rather than catastrophic: earthquakes in 956 CE, 1303 CE and 1323 CE each removed sections, and the tower was progressively stripped for building material.
By the time the Mamluk sultan Qa'itbay built his fortress on the site in 1480, the Pharos had been reduced to its lower courses. The fortress of Qa'itbay, which stands today as the Citadel of Qaitbay, was built partly from blocks salvaged from the lighthouse. Underwater archaeological surveys conducted from the 1990s onwards have found the remains of large stone blocks, column drums and sphinxes in the harbour off the Qaitbay headland, some identifiable as Ptolemaic construction and possibly from the Pharos itself. The site is now protected as an underwater archaeological zone.
The Word That Outlived the Tower
The most enduring legacy of the Pharos of Alexandria is linguistic. In French, a lighthouse is a phare; in Italian and Spanish, a faro; in Portuguese, a farol; in Romanian, un far. The word entered these languages through the Latin pharus, itself borrowed from the Greek pharos — the island name that had become synonymous, through the fame of its lighthouse, with the thing itself. The Arabic word for lighthouse, manara, is a separate etymological thread, but faro and its cognates appear in all the Romance languages as unambiguous testimony to the reach of the original building's reputation.
This linguistic persistence says something significant about how the ancient world received the Pharos. It was not merely a useful structure; it was a defining one — the lighthouse by whose name all subsequent lighthouses would be known. The Seven Wonders of the Ancient World, the classical canon compiled by Hellenistic scholars to describe the most extraordinary man-made structures of the Mediterranean, included the Pharos as the most recent of the seven, and the only one with a practical function. The Colossus of Rhodes, the Hanging Gardens, the Mausoleum at Halicarnassus were monuments. The Pharos was a working building, and it worked for perhaps 1,500 years.
What Remains
Nothing of the Pharos stands above water. The Citadel of Qaitbay, built on the same peninsula, incorporates some of its stone. The underwater remains documented by archaeologists give an idea of the scale of the structure, and architectural historians have produced detailed reconstructive drawings based on the textual sources and the underwater evidence. These reconstructions suggest a building of considerable sophistication: the lower square section alone was over 55 metres tall, wider than most classical temple enclosures.
The site is now the easternmost point of the modern Corniche, the seafront road that runs along the Alexandrian waterfront. The Citadel is open to visitors. The waters offshore, where the blocks lie in four to eight metres of water, are accessible to recreational divers under Egyptian heritage regulations, though excavation requires a permit. The pharos/faro/phare is everywhere — in signage, on navigation charts, in the names of the lighthouse authorities of a dozen countries — and the building that generated all of it is a scatter of blocks on a harbour floor.
To see the full network of lighthouses that descend, conceptually and technically, from the world's first great lighthouse, Open the map.