In 1810, Mendoza joined the insurgent movement started by wealthy Caracan citizens against the Spanish crown,[1] and in 1811[3] was elected to represent the province of Barinas in the newly founded Constituent Congress of Venezuela.

[4] In 1813 Mendoza fled a royalist invasion and moved to Grenada,[1] and soon after he joined Simon Bolivar's effort to liberate South America from Spanish rule.

[1][2] Fleeing Venezuela again in 1814 when José Tomás Boves conquered Caracas,[2] Mendoza moved to Trinidad,[1] where from 1819 and 1820[5] he was an active political writer for the Correo del Orinoco.

[1] In 1826,[2] Francisco de Paula Santander appointed Mendoza as Mayor of the Department of Venezuela in the empire of Gran Colombia.

After a short exile under General Jose Antonio Paez,[1] in 1827 Bolivar re-appointed him Mayor of the Department of Venezuela,[2] a role Medoza kept until resigning[1] in the middle of 1828.

[2] After obtaining his law degree, Mendoza moved to Barinas, where he became known for defending local tribal groups and helping invest their profits in several agricultural properties.

[1] In May 1810, he was elected the secretary of the newly created Board of Local Government of Barinas,[2][1] and he also led a movement among Caracas' wealthy citizens with the slogan "Peace and tranquility are our desires.

[1] During the War to the Death initiated by Bolivar in Trujillo on 15 June 1813, Mendoza served multiple functions, including "political administration, taxes, provisions, stores and changing rooms for the army, hospitals, civic patrolling and surveillance of spies.

[1][2] In Caracas,[2] Mendoza formally proposed holding the Open Meeting held on 14 October 1813 where Bolivar was granted the title Liberator.

A popular assembly on 2 January 1814 ratified Bolivar as the supreme commander of the Liberation Army (Ejército Libertador) fighting for independence from Spanish rule.

[1] Between 1819 and 1820,[5] while in Trinidad Mendoza supported the cause of the Republic of Venezuela by writing newspaper articles under the pseudonym "a patriot" for the Correo del Orinoco.

[2] While in this role, Mendoza continued to study law and history, while also editing El Observador Caraqueño along with Francisco Javier Yanes.

[better source needed] While in his new position, Mendoza tried and failed to quell tensions between opposing parties in Venezuela, in an effort to avoid more conflict and civil war.

Mendoza was exiled from Venezuela by General Jose Antonio Paez, and fled to the island of Saint Thomas[1] on 27 November 1826, with his family remaining in Caracas.

[2] According to essayist Luis Britto Garcia, Mendoza's resignation was potentially motivated by new tax measures,[clarification needed] with Britto writing "The mere announcement of rigorous tax measures strikes fear into the hearts of civil servants like the Intendant Cristóbal Mendoza, who suddenly tendered his resignation.

[2] On his deathbed, he wrote his political will in a letter to Bolívar where he stated his possessions as being "the remembrance of my weak services for the republic and the memories of our lifelong friendship.

[3] Bolivar purportedly stated about Mendoza that "you are the man I admire most in this world, because you carry and retain the model of virtue and helpful goodness.

Cristóbal Mendoza Durán, who worked as journalist in Camagüey, later joined the Liberating Army and Carlos Manuel de Cespedes, in appreciation of his intellectual and moral values, appointed him Foreign Secretary of the first government of the Republic of Cuba in Arms.