The Indian Ocean islands of Zanzibar and Pemba lie off the east African coast.
The semi-autonomous territory maintains a political union with Tanzania, but has its own parliament and president.
A former centre of the spice and slave trades, present-day Zanzibar is infused with African, Arab, European and Indian influences.
Zanzibar's original settlers were Bantu-speaking Africans. From the 10th century Persians arrived. But it was Arab incomers, particularly Omanis, whose influence was paramount.
They set up trading colonies and in 1832 the Omani sultan moved his capital from Muscat to Zanzibar, which had become a major slave-trading centre. Zanzibar became an independent sultanate.
The slave trade was abolished in 1873 and in 1890 the British declared Zanzibar a protectorate. In 1963 the islands regained independence, but upheaval was around the corner.
In January 1964 members of the African majority overthrew the established minority Arab ruling elite. The leftist revolution was swift but bloody; as many as 17,000 people were killed.
A republic was established and in April the presidents of Zanzibar and Tanganyika, on the mainland, signed an act of union, forming the United Republic of Tanzania while giving semi-autonomy to Zanzibar.
Under international pressure, Zanzibar held multi-party elections in 1995, which were won by the ruling, pro-union Chama Cha Mapinduzi (CCM) party. The opposition Civic United Front (CUF) rejected the outcome and alleged vote rigging. Political violence ensued.
The CCM won troubled polls in 2000 and 2005, both characterised by violence and fraud accusations. In 2000 many CUF supporters fled to Kenya after deadly clashes with police. Both parties signed a reconciliation agreement in 2001, but political tension persisted.
In protest against the 2005 election result, the CUF boycotted the island's parliament for four years, rejoining in 2009 in order, it said, to prevent violence in the run-up to the upcoming fresh elections.
Voters in a July 2010 referendum accepted proposals for rival political parties to share power. The reform followed a gradual rapprochement between the CCM and CUF.
The CCM wants Zanzibar to remain part of Tanzania. But the CUF, which has strong support among the descendants of the deposed Arabs, has called for greater autonomy. Some CUF members want independence.
Tourism is Zanzibar's newest and biggest industry. But most Zanzibaris have yet to benefit from it; the average wage is less than $1 per day.