[3] The Subanens were believed to be the first people to have settled in this land, right near the swift flowing river that now traverse the Margosatubig Pilot School and Guiwan district.

“Malagus Tubig” was the original name of the town, which was taken after the swift river current that kept changing its course towards the mouth of Dumanquilas Bay.

They built a huge stone fort on top of a hill that served as their bastion against Moro pirates who used to raid the settlements along the Dumanquillas Bay and its vicinity.

17 dated December 23, 1936 signed by President Manuel L. Quezon, Margosatubig finally became a regular and distinct municipality with eight original barrios.

In 1950, the barrios of Punta Flecha, Pitogo, Qugbay, Balong-balong, Libertad and Dumanguilas were transferred to the newly created town of Dimataling[5] In 1951, through issuances from President Elpidio Quirino, twenty barrios were organized into separate municipality of Malangas;[6] while ten more were also separated for the creation of Alicia.