 Throughout this brief period, however, Catholic missionaries continued their avid proselytization, converting entire clans of Subanen, Samals, Yakans and Tausugs to Catholicism, adding to the growing Visayan populations brought in primarily from Cebu and Panay.Historical records about Basilan shifted then to the archives found in the Royal courts of the maritime power that is right next door - the Sulu Sultanate.The sultanate of Sulu became a center of power in the 18th century, ruled over the island of Basilan nominally, and had little influence over the Yakan who were gradually driven far into the island's interior (Sherfan 1976