Zanzibar
Zanzibar (; ; ) is a semi-autonomous region of Tanzania. It is composed of the Zanzibar Archipelago in the Indian Ocean, off the coast of the mainland, and consists of many small islands and two large ones: Unguja (the main island, referred to informally as Zanzibar) and Pemba Island. The capital is Zanzibar City, located on the island of Unguja. Its historic centre is Stone Town, which is a World Heritage Site.
Omanis
Omani presence in the Swahili Coast can be traced since the Nabhani dynasty. In the late seventeenth century, Zanzibar became part of the overseas holdings of Oman after Saif bin Sultan, the imam of Oman, defeated the Portuguese in Mombasa, in what is now Kenya. 
Large numbers of Omanis settled in the Swahili Coast — especially after 1832, when the Omani Sultan Said bin Sultan moved his court to Zanzibar. To the Omanis, the region became a land of economic opportunity. Omanis who migrated to the Swahili Coast looked forward to a better life. The Omani community in the Swahili Coast grew and became financially successful.
Until the middle of 20th century Omanis stopped moving to Zanzibar after a revolution has occurred in Zanzibar in 1964. The Omani descendant, sultan of Zanzibar, Sultan Jamshid bin Abdullah was overthrown, and thousands of Omanis were killed, among many other Arabs. Soon after the revolution, many Omanis fled Zanzibar to avoid persecution and returned to their ancestral homeland Oman, while others chose to remain in the Swahili Coast.