During the Revolution, Llanera took command of Nueva Ecija, his home province. He welcomed Aguinaldo to Biyak-na-Bato after retreating from Cavite in June 1897 and joined him in Hong Kong in December that same year. As municipal mayor of Cabiao, Nueva Ecija, during the last few years of the Spanish regime, Mariano Llanera led the Katipuneros of his region, to attack the Spanish garrison in San Isidro. Following this attack, which started the uprising in that province, he captured Aliaga and then fought in Umingan, Pangasinan. Some 18 months later, in compliance with the terms of the Pact of Biyak-na-bato, he sailed for Hongkong as an exile together with General Aguinaldo. He returned to the islands to resume the Revolution in June 1898, as a Lieutenant-General. In February 1899, when Filipino-American hostilities broke out, he fought the enemies from Caloocan to the north. He was captured and subsequently exiled to Guam on January 16, 1901. After taking the oath of allegiance to America he returned to his province. Llanera, the revolutionary general who used a distinctive black banner with a skull over two crossed bones and a big, white "K" inscribed on it, was born to Enrique Llanera and Juana Nuñez in Cabiao, Nueva Ecija, on November 9, 1855. Though he attended Letran, he did not finish his segunda enseñanza. Nevertheless he became a cabeza de barangay and twice gobernardorcillo of Cabiao during the last years of the Spanish regime. He died on September 19, 1942. In all, he had 14 children. His first wife was Salome Siao-Paco whom he had married in 1877 and his second wife was Feliza Balajandia whom he had married in 1919.