When Aglipay returned to Manila and discovered that the Americans had attacked, he joined the revolution. On 20 October 1898, Gen. Aguinaldo appointed Aglipay Military Vicar General of the revolutionaries. Aglipay interpreted this as making him Ecclesiastical Superior to all Filipino priests who, as such, should all be appointed Military Chaplains for the duration of the war. Fighting which broke out between the U.S. and Filipino forces on February 4, 1899 prompted Aglipay to withdraw to Ilocos Norte to organize an armed resistance. On 29 April 1899, Aglipay was excommunicated for "usurpation of ecclesiastical jurisdiction.