Dee Ann Hansen, age 13, of Austin, Texas, for her question:
HOW OLD IS CAIRO, EGYPT?
In the early A.D. 630s, Egypt was a province of the Byzantine, or East Roman Empire. Its people were Christians and were descendants of the ancient Egyptians who founded a great civilization along the Nile River as early as about 3100 B.C.
Arabs from east of Egypt conquered the province in the A.D. 640s. These Arabs built a military camp in the area that is now southern Cairo. They later built houses, mosques and palaces and the camp soon became a real city.
Not too far from the settlement were reminders of ancient Egypt. They were the pyramids and the Great Sphinx which stand at Giza in the desert west of what is now Cairo.
Arabs from North Africa called the Fatimites conquered Egypt in 969 and made Cairo their capital. They built up the area north of the first Arab settlement and Cairo soon became one of the most important cities of the vast Arab world.
The Fatimites founded the University of A1 Azhar, which attracted students of Islam from many countries. The Fatimites called their city A1 Qahirah because the planet Mars, A1 Qahir in Arabic, was rising in the sky when they began building. The name Cairo comes from A1 Qahirah.
Saladin, the founder of Egypt's Ayyubid dynasty or family of rulers, expanded the city's boundaries and built the Citadel in the late 1100s. The Mamelukes, who had served the Ayyubids as bodyguards, ruled the country from 1250 to 1517. They built many of Cairo's finest mosques and extended the city to its present boundaries.
The Ottoman Turks controlled Egypt from 1517 to 1882. They allowed the Egyptians a large degree of self government.
Many of the treasures of ancient Egypt were discovered in the early 1800s. Exhibitions and lecturers about Egypt's past brought thousands of visitors to Cairo to see the wonders.
Many people from Europe settled in Cairo during the 1800s when European nations became increasingly involved in Egypt's affairs.
A program to modernize Cairo started about 1865. The program continued during the British rule of Egypt from 1882 to 1922 and during the Egyptian monarchy from 1922 to 1953.
Egypt became a republic in 1953. The government since then has done much to modernize Cairo, but extreme poverty still exists in many parts of the city.
Cairo's rapidly growing population contributes to the poverty problem. The city's population increased from about 375,000 in 1882 to more than 3.5 million in the 1960s. Today it is well over 5 million.
The growth of Cairo's population is a result of Egyptian families moving from rural parts of the country, refugees who moved from Ismailia, Port Said and Suez and a high birth rate.
Cairo has hot summers and mild winters. The city receives only about one inch of rain each year.