Islam in Tanzania: history and Muslim population data

History of Islam in Tanzania

The United Republic of Tanzania has an area of 947,300 sq km, including the islands of Mafia (422 sq km), Pemba (984 sq km), and Unguja or Zanzibar (1,575 sq km). The last two islands and small islands surrounding them comprise the semi-autonomous region of Zanzibar.

The mainland was occupied by the Germans in 1884 but they lost it to the British between 1914 and 1919. The British also occupied the Islands of Zanzibar in 1919. The mainland was named Tanganyika by the British in 1920. Tanganyika and Zanzibar gained independence from the UK in 1961 and 1963, respectively. They united in 1964 to form Tanzania, where the name is formed using the first three letters of each of the two united countries.

Islam entered the eastern coast around 830 through Muslim traders from the Arabian Peninsula. Eventually, Ali ben Hassan established the Kilwa Sultanate, which lasted until it was conquered by the Portuguese in 1508. By the end of the seventeenth century, the Portuguese were driven out with the help of the Sultanate of Oman, which claimed these lands in 1698. In 1861, with the help of the British, this African side of the Sultanate of Oman was separated as Zanzibar Sultanate.

According to DHS survey data, the percentage of Muslims was 32.05% in 1992, 30.57% in 1994, 31.11% in 1996, 32.60% in 1999, 30.25% in 2004 and 30.13% in 2005. The ABS put it at 29.38% in 2003, 25.20% in 2006, 28.91% in 2009, 35.40% in 2012 and 31.79% in 2015.

Thus, assuming that the percentage of Muslims will increase by half of a percentage point per decade; then the Muslim population is expected to increase to 43 million or 33.5% by 2050 and 88 million or 36% by 2100.

Historical Muslim population dataset for Tanzania

The figures below are from the CoMPS historical dataset. Population values are expressed in thousands; 2100 is a modelled projection, not a present-day count.

For the full time series and visualisation, use the interactive map above.