He was born on June 24, 1770 in La Asunción. Son of the militia captain Miguel Arismendi and Mariana Subero. In 1790, he began his career as cadet in a militia battalion of Margarita Island. In 1804, he married María Del Rosario Irala with whom he had seven children. In 1810, the Provisional Board of Margarita Island promotes him to Colonel. In January 1812, he was part of the expedition that sailed from Cumaná to Guayana, in order to take control of that region.

   

    In the first months of the year 1813, his wife passes away, Arismendi returns to Margarita and directs an uprising against the government of Pascual Martínez, who ends up dead. Afterward, he moved to Caracas and recognized Simón Bolívar as the Supreme Chief of the Republic. He returned to the island in April 1814 and on December 2, he married Luisa Cáceres.

     

    On January 8, 1815, a triumvirate assumed the political Government of the Margarita Island and they entrusted to Colonel Arismendi the command of all the armed forces of the Island. In March, the Spanish expedition led by Pablo Morillo arrived to the island However, they did not develop any combat. In 1815, the Royalist troops captured Luisa Cáceres in order to exert pressure on her husband. Consequently, he expressed “tell to the Spanish leader that without sovereignty over the territory, I do not want a wife”.