Oman Captures Zanzibar

Portugal’s decline during the 1600’s led to cracks in its control of East Africa. Oman took advantage of Portugal’s weakness to seize Zanzibar by 1701, effectively ending Lisbon’s rule north of Mozambique.

Summary of Event

For centuries the richest place in Africa, Zanzibar was the lucrative hub of trade routes between Africa, Arabia, and India, supplying slaves, gold, ivory, spices, tortoiseshell, and mangrove poles in exchange for textiles, metalwork, and glass. From the eighth century onward, lateen-rigged wooden sailing ships, or dhows, used trade winds to sail northeast to India and Persia during the spring and summer, then back in the autumn and winter. [kw]Oman Captures Zanzibar (c. 1701)
[kw]Captures Zanzibar, Oman (c. 1701)
[kw]Zanzibar, Oman Captures (c. 1701)
Zanzibar, seizure of (c. 1701)
Portugal;colonization of East Africa
Colonization;Portuguese of East Africa
[g]Portugal;c. 1701: Oman Captures Zanzibar[0020]
[g]Africa;c. 1701: Oman Captures Zanzibar[0020]
[g]Oman;c. 1701: Oman Captures Zanzibar[0020]
[c]Expansion and land acquisition;c. 1701: Oman Captures Zanzibar[0020]
[c]Wars, uprisings, and civil unrest;c. 1701: Oman Captures Zanzibar[0020]
Saif I ibn Sulṭān
Sulṭān bin Saif
Balՙarab bin Sulṭān

The eighteenth century region of Zanzibar included what is now Zanzibar Island, as well as portions of modern Kenya and Somalia, but the island of Zanzibar was its center. Locally known as Unguja, Zanzibar is a limestone island, fifty-three miles north to south and twenty-four miles east to west. It is located in the Indian Ocean some forty miles by boat from Dar es Salaam, the modern capital of Tanzania. Arabs called the eastern African coast and its adjacent islands Zinj el Barr, Zinj el Barr (land of the blacks) or “Land of the Blacks.” This served as a general designation until the late 1400’s, after which the name was used only for Unguja. Historically tied to Zanzibar are Pemba Island, which lies about thirty miles north, and the smaller Mafia Island seventy-five miles south. As Zanzibar is located 6 degrees south of the equator, hot, humid weather moderated by frequent breezes prevails. Heavy rains from March to May and lesser rains in October and November water the region.

Portuguese navigator Vasco da Gama Gama, Vasco da landed in Oman on his way to India in 1498 and visited Zanzibar on his return voyage. At that time, the most important place in East Africa was the Shirazi gold trading center of Kilwa, built a mile off the coast in the 1200’s. The accounts of both fourteenth century Arab traveler Ibn Baṭṭūṭah Ibn Baṭṭūṭah and sixteenth century Portuguese sailors attest to Kilwa’s importance. Lisbon gained control of Zanzibar; soon conquered Kilwa, Pemba, Mombasa, Lamu, and Hormuz; and sacked Muscat. Gold trading was rerouted, and Kilwa declined. However, far from its European base, Portugal’s far-flung empire was challenged by Omani Arabs, Omani Arabs who had plied the Indian Ocean from the eastern end of the Arabian peninsula for centuries.

Oman’s imams, often mistakenly called sultans, ruled from the inland mountain fortress of Rostaq. However, increasing interest in seaborne trade and naval power led them to focus on Muscat, their main port and eventually their capital. In 1649, Imam Sulṭān bin Saif defeated the Portuguese at Muscat and chased them to India. The ships he captured proved superior to his dhows in firepower and formed the core of a rebuilt Omani navy. Following his victory, the imam, bolstered by ten thousand soldiers and twenty-eight ships, arrived in Zanzibar to aid the island’s exiled Queen Mwana wa Mwana. Sacking Portuguese settlements on Zanzibar and Pemba, he took four hundred prisoners. The Portuguese dead included Viceroy Manoel de Nazereth. Before returning to Oman, Sulṭān bin Saif appointed a member of the El-Harthy family to rule Zanzibar.

Sulṭān bin Saif had come to power in accordance with a nine-hundred-year-old tradition of elections. However, his dying decree handed power to his son, Balՙarab bin Sulṭān. Thus began Oman’s hereditary succession. Sulṭān’s descendants, the Yaՙrubi Dynasty, Ya{ayn}rubi Dynasty[Yarubi Dynasty] established a trading empire stretching from Kilwa in east Africa to Gwadar in present-day Pakistan. However, the Portuguese challenge continued. In 1686, Portugal had captured and executed the Sultan of Pate. Delegations from both Pate and the Shirazi of Zanzibar went to Muscat seeking help from Imam Saif I ibn Sulṭān as a fellow Muslim.

Between 1696 and 1698, the Omanis under Saif I ibn Sulṭān expelled the Portuguese from Zanzibar Island, captured Fort Jesus in Mombasa, and stormed the Portuguese fortress on Pate, forcing the Europeans to withdraw south to Mozambique. An exact date of the final demise of Portuguese power in Zanzibar is debatable, but the Omanis were clearly in control of the coast north of Mozambique by 1701, by which time Zanzibar Island had become an Omani stronghold.

The island’s defenses were strengthened with the completion of a fort armed with cannon from Sulṭān bin Saif’s eighty-gun flagship Al-Falaq (the dawn). Built between 1698 and 1701 on the ruins of a Portuguese chapel, this quadrilateral fort dominated the town with high, dark brown walls topped by crenellated battlements and turrets. From here, the Omanis controlled one thousand miles of the mainland coast from Somalia to Mozambique.

The Arab hold on the area was consolidated with the establishment of a trading post, garrison, and prison on Kilwa. Portuguese attempts to recolonize Mombasa in 1699, 1703, and 1710 failed. Queen Mwana wa Mwana returned to Zanzibar from Yemen in 1710. However, her successors were overshadowed by Omani governors. Small and easy to defend, the islands provided ideal bases for the Arabs, who had learned well from their enemies.

While Zanzibar’s Arabs continued to pay allegiance to governors appointed by the imam in Muscat, they enjoyed much autonomy. The mainstay of their economy was trade. Arab caravans reached into Africa’s interior, a lucrative area for slaves Slave trade;Africa and ivory. Over a period of almost four centuries, between 700,000 and 1.2 million slaves were taken from the mainland. Numbering sixty-five hundred per year by 1834, slaves from as far away as Malawi and Uganda were shipped through Zanzibar to the Middle East and India. Most wealth remained in the hands of Omani landowners and traders, who isolated themselves and seldom intermarried with Africans.


Political stability did not accompany Oman’s wealth and new territories. Although the Portuguese ceased to be any threat after 1730, new difficulties arose. Beginning with an invasion by the Persians during a succession dispute in 1737, Oman cycled between periods of trade-generated prosperity and bitter strife within its ruling class. Taking advantage of this situation, the Arab governor of Mombasa declared his independence in 1741 and established the Mazrui Dynasty, Mazrui Dynasty which ruled the Kenyan port city until it was reintegrated into Zanzibar in 1837. Also in 1741, Aḥmad ibn Said defeated the Persians and, returning to an earlier tradition, was elected imam in Oman. Upon his death, hereditary succession continued in the form of a new dynasty, the Busaidi, Busaidi Dynasty which has continued in power to the present. However, Arab power in the region had by then been supplanted by European empires.

Omani fortunes appeared to improve in 1820, when Imam Said ibn Sulṭān, also known as Sayyid Said, expelled the Wahabis, rebuilt his navy, and strengthened his empire with British help. Under his guidance, the Swahili Coast’s fertile lands were transformed. Around 1818, sailors returned from Indonesia with cloves, a hitherto unknown spice that thrived on East Africa’s islands along with more than fifty other spices and fruit. Most Hadimu and many slaves from the mainland were forced to work on plantations, which eventually produced a third of the imam’s revenues. Officially transferring his court to Stone Town, Said ignored troubled Oman and devoted his efforts to Zanzibar, from which Islamic and Arab influence spread. Furthering Oman’s decline, many Arabs departed for better lives in Africa, where they built the palatial coral-stone homes with ornate carved doors and balconies that still characterize Zanzibar and the Swahili Coast.

Further Reading

  • Alpers, E. A. Ivory and Slaves in East Central Africa to the Later Nineteenth Century. London: Heinemann, 1975. A good account of Zanzibar and the east African slave trade.
  • Hawley, Donald. Oman and Its Renaissance. London: Stacey International, 1984. This official reference on Oman includes much on the imams and Zanzibar.
  • Moorehead, Alan. The White Nile. New York: Penguin, 1971. Moorehead’s exciting account of European influence in east and northeast Africa begins with a chapter on Zanzibar during the late Omani period.
  • Segal, Ronald. Islam’s Black Slaves: The Other Black Diaspora. New York: Farrar, Straus and Giroux, 2001. An analysis of the thousand years of slave trading between Africa, India, and the Middle East, including much on Zanzibar.
  • Strandes, Justus. The Portuguese Period in East Africa. Translated by Jean F. Wallwork. Edited by J. S. Kirkman. Nairobi, Kenya: East African Literature Bureau, 1961. Excellent source on Portugal’s African empire.

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