He was one of the main figures of the Chilean independence process, being the final Spaniard to rule as Royal Governor of Chile from 1815 to 1817, when he was deposed and captured by the patriot forces after the Battle of Chacabuco.

Once he assumed the head of the Reconquista government he sent spies to Cuyo in order to obtain information about the Army of the Andes being amassed by exiled pro-independence leaders such as Bernardo O'Higgins in the Argentine province of Mendoza.

A number of notables were deported to the barren Juan Fernández Islands, and others suffered the depredations of group of soldiers led by the infamous captain Vicente San Bruno.

The governor Marco del Pont tried to escape to Valparaíso to catch a transport leaving for Peru, but he was intercepted by an advance column of the patriot army at an hacienda called "Las Tablas" near El Quisco.

His days ended after a final move to the hacienda of Pedro Ignacio de Mujica, near Renca, in Luján a city close to Buenos Aires, when he died in prison in 1819.