His revolt was fueled by grievances stemming from Spanish taxation and abuses, and by his belief in self-government, that the administration and leadership of the Roman Catholic Church and government in the Ilocos be invested in trained Ilocano officials.
"Diego de Silang, a Filipino, very quick and artful, and who being a native of Manila [ie island of Luzon], spoke the Spanish language well, began to revolutionize this province, by telling his countrymen, that in order to maintain the Catholic faith, and to preserve the country in obedience to the King, it was requisite to join together and arm against the Spaniards, and deliver them up to the English, against whom they had no means of resistance.
The majority advised the Alcalde to defend himself against this attack; but instigated by his fears, or swayed by the opinion of injudicious friends, he resigned the command to the Vicar-general, and with no inconsiderable share of hazard of his life, effected his escape from the province.
Emboldened by their success in this instance, the rebels demanded of the Bishop elect, Señor Ustariz, a Dominican, an exemption from the tribute, declaring that they acted justifiable in deposing the Alcalde.
The Bishop pledged himself to lay before Señor Anda a favourable representation of their claims; but Silang being determined on acquiring the command, and little satisfied with what he had done, began to collect troops for more extensive operations."