Magalahi (Chief) Mata'pang was a member of the highest caste of Chamorros (the indigenous people of Guam) called Chamorri. He was baptized by San Vitores, but later turned against the Spanish mission.
On April 2, 1672, Mata'pang, aided by Hirao, killed Padre San Vitores and his Filipino assistant, Pedro Calungsod. Padre San Vitores had baptized Mata'pang's daughter without the Chief's permission. Some say that Mata'pang had believed holy water used in baptism had caused the recent deaths of babies due to European diseases.
Spanish soldiers attempted to hunt down the missionary's killers. Shortly after the murder, Hirao was caught and killed. Mata'pang was shot by a musket while taunting his pursuers as he sailed past the beach of Tumon on a proa. The chief fled to the northern island of Rota. In 1675, Spanish soldiers burned a village while trying to capture him, but Mata'pang escaped. Eventually, the Spanish military governor, Jose de Quiroga, increased efforts to subdue the Chamorros. In 1680, fearing the governor, Chamorros on Rota injured Mata'pang while capturing him and transported him to Guam by proa. The wounded chief died during the journey.