Although he is sometimes called the "forgotten friar," Fermín Lasuén actually governed the California Mission system three years longer than his more famous predecessor, Junípero Serra. Lasuén was born at Vitoria in Álava, Spain on July 7, 1736 and joined the Franciscan order as a teenager, entering the Friary of San Francisco shortly before his fifteenth birthday on March 19, 1751. On March 19, 1751, Lasuén was ceremoniously invested with his Franciscan habit.
In 1759, Lasuén left the Franciscan Sanctuary of Arantzazu (Gipuzkoa). He then set sail from Cádiz with seventeen other friars while still a deacon to volunteer for ministry in the Americas. He arrived in New Spain in 1761 and was sent west to Las Californias in 1768. Following the establishment of Mission San Diego de Alcalá in 1769, he moved north to Alta California in 1773. He based himself in San Diego and remained there until 1775; he helped establish Mission San Juan Capistrano before the murder of Luís Jayme. Kumeyaay Indian unrest caused his return to San Diego.
In late 1776 he went to San Luis Obispo before again returning to San Diego in 1777 when he was made minister there. He was appointed the second Presidente of the missions in California in 1785, following the death of Junípero Serra, and transferred to the Mission San Carlos Borromeo de Carmelo. Lasuén continued the work begun by Serra, establishing 9 more missions, bringing the total to 18 (the final total was 21). He died at Mission San Carlos Borromeo de Carmelo on July 26, 1803. On his death he was succeeded by Esteban Tápis.