The Arab Muslim invasion began in 712 AD at the Sindh Valley and by around 1300 AD they had taken over the entire northern India. However, even prior to the invasion there were Arabs in southern areas such as Calicut, Quilon and Malabar, chiefly traders interested in the spices, pearls, precious stones and cottons which were available there. Another advantage of the location was that it was on a major sea trade route running through south-east Asia and on to China. Some of these Arabs were also pearl divers, having gained their experience in the waters of the Persian Gulf. Some Paravars adopted Islam, whose women also were married off to Muslim traders. These claimed to be descendants of the biblical figure Noah.