The Plan de Guadalupe, signed in Coahuila on March 26, 1913, launched the Constitutionalist movement of the Mexican Revolution. Its fourth article names Venustiano Carranza, governor of Coahuila, as “Primer Jefe del Ejército que se denominará ‘Constitucionalista'” (First Chief of the army that will be called Constitutionalist). (Video in Spanish.)
Its fifth article provides that Carranza will take charge of the executive power on an interim basis once the army occupies Mexico City.