Junípero Serra spent eight years on the project of building the missions until 1770. When a number of historical events, including the expulsion of the Jesuits, forced the abandonment of the missions. Serra moved on to California. When Serra left, the missions were left in the hands of regular clergy. During both the Mexican War of Independence and the Mexican Revolution, the missions suffered sacking and destruction. Initial restoration work to the outside of the mission churches was begun in the 1980s. Between 1991 and 1997, interior work on altars, choirs, organs and paintings was done. Further work was sponsored by the state between 1997 and 2002. Work done in the 1990s also included that on surrounding plazas and monuments. The effort to inscribe the missions as a World Heritage Site began in 2000 and was ultimately successful in 2003, when it was added during the 27th meeting of the World Heritage Committee.