Islam is the religion of approximately 11.1 percent of the Kenyan population, or approximately 4.3 million people. The Kenyan coast is mostly populated by Muslims. Nairobi has several mosques and a notable Muslim population.
The vast majority of Muslims in Kenya follow the Sunni Islam of Shafi school of jurisprudence. There are also sizeable populations of Shia and Ahmadi adherents. In large part, Shias are Ismailis descended from or influenced by oceanic traders from the Middle East and India. These Shia Muslims include the Dawoodi Bohra, who number some 6,000-8,000 in the country.
Pioneer Muslim traders arrived on the Swahili Coast around the eighth century. The tension surrounding the succession of Muhammad, the prophet of Islam, and the already established trade links between the Persian Gulf and the Swahili Coast were some of the factors leading to this development.
Archaeological evidence attests to a thriving Muslim town on Manda Island by the Tenth Century AD. The Moroccan Muslim traveller, Ibn Battuta, visiting the Swahili Coast in 1331 AD, reported a strong Muslim presence. Ibn Battuta said: The inhabitants are pious, honourable, and upright, and they have well-built wooden mosques.
On arrival, the Muslims settled along the coast, engaging in trade. The Shirazi intermarried with the local Bantu people resulting in the Swahili people, most of who converted to Islam. Swahili, structurally a Bantu Language with heavy borrowings from Arabic, was born.
Primarily, Islam spread through the interactions of individuals, with the Arab Muslims who had settled in small groups maintaining their culture, and religious practices. Despite encountering local communities, Islam was not ‘indigenized’ along the patterns of the local Bantu communities. Nevertheless, Islam grew through absorption of individuals into the newly established Afro-Arabic Muslim communities. This resulted in more ‘Swahilization’ than Islamization.