What lurks behind the wooden doors of Zanzibar? Teak double-doors set with rows of iron studs -- or spikes to repel attacking elephants -- decorate the streets of Stone Town, the oldest part of Zanzibar City. Ornate carvings frame the doors and speak of mystery and wishes. Do the carvings depict chains? The householder hopes for security. Fanciful fish? A couple wishes for many children. Illustrated passages from the Koran? Devout Muslims live inside.

Zanzibar was the richest place in Africa for centuries, an island burgeoning with spices and subject to such favorable winds that it served as the center of trade between Africa, Arabia and India. Actually a group of islands, "Zanzibar" forms half the name of "Tanzania." In 1964, the islands joined with Tanganyika, the country 22 miles away on the eastern coast of the African mainland, to become the United Republic of Tanzania.

The largest island of Zanzibar, more properly known as Unguja, stretches 53 miles north to south and 24 miles east to west in the Indian Ocean. White sand beaches grace the shores, where occasionally moonstones, zircons and garnets wash up on the turquoise tide. Coral reefs along Unguja and Pemba, a smaller island to the north, offer some of the best snorkeling in the world. Swahili is the language spoken by Zanzibar's population of about 800,000 persons of Arab-African origin and Islamic faith.

Hot and humid weather prevails, as the island lies just six degrees south of the equator, but breezes blow almost constantly. For five thousand years, trade winds have blown ships northeast from Zanzibar to India and Persia during the spring and summer, then reversed direction to bring back the heavy, teak boats with lateen sails called dhows during fall and winter. Their cargo was ivory, gold, spices and slaves, but today the principal export is cloves, dried buds of the clove trees that grow on plantations that were established in the early 1800s by Sultan Said of Oman, a country along the east coast of Saudi Arabia.

Slavery was vigorously opposed by the missionary David Livingstone, the Scots physician of "Doctor Livingstone, I presume" fame. Livingstone inspired world-wide opposition to slavery in the latter half of the nineteenth century by writing about the horrific treatment of people captured in Africa by Arabs or warring African tribes, kept in caves on Zanzibar, sold at auction in Zanzibar Town, and shipped to Arabia, Persia, India, and America. The Anti-Slavery Society continues to fight slavery, concentrating recently on the treatment of Dinka people in the Sudan.

Zanzibar has been ruled by Arab sultans, controlled at various times by the governments of Portugal, Great Britain and Germany, and now takes its place under the Tanzanian government as the world's leading exporter of cloves with a growing tourist industry.

The complex colonial history of Zanzibar is most easily grasped by reference to a timeline:

ZANZIBAR OVER TIME

3000 BC Egyptians sailed the east African coast and may have landed on Zanzibar.

600 BC Phoenicians circumnavigated Africa.

1 AD Greeks and Romans sailed east African coast looking for ivory. They called the coast "Azania" and the island of Unguja "Menouthesias."

100 Kingdom of Saba ( Sheba) dominated Zanzibar and east coast of Africa. Zanzibaris still call themselves "Shirazi."

600 Arabs from Oman named the east coast of Africa "Zinj el Barr," meaning "Land of Black People." The whole east African coast and the islands of Zanzibar and Pemba were called Zanzibar until the late1400s.

900 Persians emigrated to Zanzibar but lost their separate identity as they were absorbed into two Islamic groups, the Hadimu and Tumbatu. Omani Arabs continued to dominate the islands from the Omani capital, Muscat, and to direct trade in slaves, ivory, gold, and tortoiseshell.

1500 Portuguese ruled after Vasco da Gama sailed to India in 1923 and "discovered" the Spice Islands for Europe. During the early 1500's, Portuguese conquered Zanzibar, Mombasa, Pemba, Hormuz and Muscat.

1650 Omani Arabs expelled Portuguese from Muscat and, by 1668, reclaimed the east African coast.

1696 Omani Arabs expelled the Portuguese-supported sultanate from Zanzibar. The Sultan of Oman ruled Zanzibar from Muscat through appointed governors.

1832 The Sultan of Oman, Sultan bin Ahmed, made Zanzibar the capital of his empire

1861 Zanzibar broke free of Oman and became an independent sultanate.

1890 Great Britain declared a protectorate over Zanzibar.

1963 Zanzibar joined the British Commonwealth.

1964 Zanzibar and Tanganyika united to form "Tanzania," a republic. Africans ousted the Arab ruling class from Zanzibar.