As the Second Mexican Empire was being established in 1863, the Assembly of Notables elected him as part of the executive triumvirate that invited Maximilian of Habsburg to take the throne.

After receiving his primary education, he joined the military and participated in the Mexican War of Independence as an infantry cadet in the Infantes de Puebla regiment.

He joined in the Plan of Jalapa against Vicente Guerrero, but defended the subsequent government of Anastasio Bustamante when the San Luis Potosí militia rose up.

[3] During the Centralist Republic of Mexico he participated in the war against Texas and was present at the Battle of the Alamo, and returned to Matamors after the decisive defeat at San Jacinto.

[4] Four years later he was named commandant general of Mexico and was one of the few individuals that remained loyal to Santa Anna when he was overthrown in 1844, for which he was removed by the triumphant rebels from his military posts.

When Mariano Paredes assumed the presidency in 1846, he returned him to the post of commandant general and he was named deputy to the constituent congress that was meant to meet later in the year and draft a new constitution.

He prohibited political controversies in the official state newspaper, and permitted Valentin Canalizo, who had been banished with Santa Anna, to return to the country and offer his services for the war effort.

[9] Salas formed his cabinet out of liberals and Santa Anna supporters, including ex president Valentin Gomez Farias who now received the post of finance minister.

Before accepting their posts, the ministers presented a plan for suppressing interior tolls, reforming autocratic laws, and promoting European immigration, but all based upon the continuation of the war supported by the union of the military and the people.

Minister of War Juan Almonte asked the states to organize their national guards, set prices at which arms should be bought, and sent General Ampudia to Monterey.

He called upon each state to contribute a contingent of thirty thousand soldiers, he named a commission to form the regulations for the national guard.

Minister Lafragua wished to establish academies of history and languages and also a public library, at the same time that the financial resources of the nation were being diverted to the war effort.

[14] The poor course of the war produced opposition to Salas and to help prevent any sort of mutiny Santa Anna sent out a manifesto assuring that he stood behind the president.

General Salas opened the session by lamenting the defeats that the military had faced, but expressed hope for the army of twenty thousand men that Santa Anna had gathered at San Luis Potosí.

[21] On 16 June 1863 a Junta Superior de Gobierno made up of thirty five prominent citizens met to elect a triumvirate that was to lead the government's executive.