Aswan Low Dam was summoned to Egypt by the Fatimid Caliph, Al-Hakim bi-Amr Allah, to regulate the flooding of the Nile, a task requiring an early attempt at an Aswan Dam. After his field work convinced him of the impracticality of this scheme, and fearing the Caliph's anger, he feigned madness. He was kept under house arrest from 1011 until al-Hakim's death in 1021, during which time he wrote his influential "Book of Optics". Following their 1882 invasion and occupation of Egypt, the British began construction of the first dam across the Nile in 1898. Construction lasted until 1902, and it was opened
Aswan 330, the legion stationed here received a bishop from Alexandria; this later became the Coptic Diocese of Syene. The city is mentioned by numerous ancient writers, including Herodotus, Strabo, Stephanus of Byzantium, Ptolemy, Pliny the Elder, Vitruvius, and it appears on the Antonine Itinerary. It also is mentioned in the Book of Ezekiel and the Book of Isaiah. The latitude of the city that would become Aswan – located at 24° 5′ 23″ – was an object of great interest to the ancient geographers. They believed that it was seated immediately under the tropic, and that on the day of