Intermittent warfare lasting from July 23, 1670 until July 1695, plus the typhoons of 1671 and 1693, and in particular the smallpox epidemic of 1688, reduced the Chamorro population from 50,000 to 10,000 to less than 5,000.:86 Precipitated by the death of Quipuha, and the murder of Father San Vitores and Pedro Calungsod by local rebel chief Matapang, tensions led to a number of conflicts. Captain Juan de Santiago started a campaign to pacify the island, which was continued by the successive commanders of the Spanish forces.:68–74