Phillip Keck, age 13, of Chattanooga, Tenn., for his question:
HOW OLD IS CAIRO, EGYPT?
Cairo is the capital of Egypt and the largest city of Africa. For more than 1,000 years it has also been the cultural center of Islam. Cairo can trace its beginnings back more than 5,000 years.
Memphis was the name of the ancient capital of Egypt. It was built at the apex of the Nile delta, just south of present day Cairo. It was believed to have been founded about 4000 B.C. and was important during the Old Kingdom between 3100 and 2242 B.C.
Memphis became a seat of the Persian satraps in 525 B.C., and the city was later ruled by the Ptolemies and Rome.
Memphis finally declined. In A.D. 641, Arabs from southwestern Asia founded the military encampment of Fustat nearby. In 969 a dissident branch of Muslims, the Fatimids, conquered Egypt, establishing a fortified city northeast of Fustat. It was called al Qahirah, meaning "the victorious." The name has been corrupted in English to Cairo.
In the 12th century, Crusaders attacked Cairo but they were defeated by a Muslin army from Syria led by Saladin, who then founded the Ayyubid dynasty in the city. Saladin built a great citadel in Cairo that is still standing.
In the 13th century the city became the capital of the Mameluke dynasty. A century later Cairo had a population of more than 500,000. No city in Europe or the Middle East could rival it in size or prestige.
Cairo was captured by the Ottoman Turks in the early 16th century and Napoleon conquered Egypt in 1798. The Ottomans regained the city in 1801 .
During the reign of Ismail Pasha between 1863 and 1879, a European style community, Ismailiya, was built to the west of the medieval city. By the beginning of the 20th century the British developed a modern urban center in Ismailiya and expanded it westward to the Nile.
Az Zamalik Island and parts of the west bank of the Nile were also built up by the British during the period they controlled Egypt.
Following World War I the foreign presence of Cairo began to drop. New residential areas were founded to house the city's growing number of workers, many of whom were migrants from rural areas of the country.
By 1927 Cairo had one million inhabitants, a number that doubled by 1947.
Cairo's population continued to grow, especially during the 1960s and 1970s. Today's estimated population is more than 5.5 million.
Today almost all Cairo is situated on the east bank of the Nile. The modern city is centered at Tahrir Square, the site of a Western style business district and government ministries. On Corniche Drive, along the Nile, are luxury hotels and foreign embassies. To the east of the business district is the extensive medieval city.