In AD 956, an earthquake shook Alexandria, and caused little damage to the Lighthouse. It was later in 1303 and in 1323 that two stronger earthquakes left a significant impression on the structure. When the famous Arab traveler Ibn Battuta visited Alexandria in 1349, he could not enter the ruinous monument or even climb to its doorway. The final chapter in the history of the Lighthouse came in AD 1480 when the Egyptian Mamelouk Sultan, Qaitbay, decided to fortify Alexandria's defense. He built a medieval fort on the same spot where the Lighthouse once stood, using the fallen stone and marble.
Most accounts indicate that it, like many other ancient buildings, was the victim of earthquakes.
A.D. Reports indicate the final collapse came in 1326. There is also an unlikely tale that part of the lighthouse was demolished through trickery. In 850 A.D. the Emperor of Constantinople, a rival port, devised a clever plot to get rid of the Pharos. He spread rumors that buried under the lighthouse was a fabulous treasure. When the Caliph at Cairo who controlled Alexandria heard these rumors, he ordered that the tower be pulled down to get at the treasure.