Archaeological evidence suggests that present-day Tanzania was inhabited by Khoisan-speaking hunter-gatherers from at least 10,000 BC. The Sandawe and Hadze of north-central Tanzania are descendants of these groups. Cushitic-speaking cattle herders migrated south from Ethiopia and Sudan from around 1000 BC. Beginning in the first millennium AD, Tanzania was settled by Bantu-speaking iron-working farmers, whose origins are considered to be in the borderlands of present-day Nigeria and Cameroon. Seafarers from Arabia established a trading settlement on the coast at Kilwa around AD 800, and Persian merchants settled on the islands of Zanzibar and Pemba. Nilotic-speaking pastoralists (including the Maasai and Luo) moved south into Tanzania between AD 900 and AD 1700. Sultan Hassan bin Sulaiman I established control of Kilwa around 1270. Islam spread and a thriving Afro-Arab ‘Swahili’ culture took hold in coastal areas.