Giangan

The Giangan, or Klata, are an Austronesian Bagobo people of eastern Mount Apo and the upper Davao river. Their Klata language belongs to the Bilic branch of Philippine languages, and their word for the river, Dawaw, blended with neighbouring peoples' names, giving the gulf and city their name.

They held Apo as their ancestral homeland, farming its slopes in swidden fields under datu leaders and sharing animist beliefs with neighbouring Bagobo. The Tagloc coast drew Bagobo, Maguindanaon and Tausug traders.

When Ruy Lopez de Villalobos's expedition passed Mindanao in 1543, it avoided the Gulf of Tagloc, fearing its Moro fleets, so European power did not touch the highlands for another three centuries. Around 1800 the Maguindanaon Datu Bago entered the gulf, won Bagobo and Giangan groups to his side, and built Pinagurasan fortress in 1830, drawing the highlanders into the Muslim port state's orbit, their villages and customs left largely intact.