What is the History of Kalagan Tribe of Mindanao?

Kalagans is literally known as the people of the shore in Davao gulf and Davao gulf also was known as the Kagan lake. They reffered to called them as "KAGAN" rather than Kalagan because they believe that this was the original Word of their tribe. They were Islamized in the middle of 15th century by the Sharrifs from Maguindano and Sulu who have a good relation and a barter trade of the Datus and Kalagan people. They are fishermens, farmers and they controlled the river key around the Davao Gulf. Their cultures is similar to their neighbor tribes, Mandaya and Mansaka and their dress code is most the same with the Maguindanaons and Tausugs. They believe magic as their tradition and medication purposes and also even they were already muslims, other Kalagans continued practicing their old pre-islamic tradition as related to the animist.