It is certain that Austronesians reached the western Indian Ocean at the end of the first millennium bce or even earlier (see below). These migrations did not come about by accident, but were based on commercial strategies embedded in evolving exchange networks throughout the Indian Ocean. It is likely that the Austronesians tried to take advantage of the demand from the West – and also from the East – transporting coveted products (above all spices), along routes that bypassed India and allowed them to reach East Africa directly. It may be within this context that Austronesians later settled in the Comoros and Madagascar.