In early 1505, King Manuel I of Portugal assigned Pêro de Anaia the duty of establishing a permanent Portuguese fortress and factory in the East African town of Sofala, at that time a reluctant vassal of the Kilwa Sultanate and major entrepot for the Monomatapa gold trade.
In late March, 1505, Anaia set out with his own ship, the Sant'Iago (also called the Nuncia) as part of the 7th Portuguese India Armada commanded by D. Francisco de Almeida.