At the age of 17 he enlisted in the royalist army participating in the campaign against the Argentine patriots in his native Upper Peru, soon He stood out in the cavalry as part of the Mounted Hunters squadron, he was promoted to lieutenant after the battle of Vilcapujio, and to captain after Viluma.

It would be in the 1823 campaign where he would notably distinguish himself to the point of receiving a special mention for his courage in the report of General Gerónimo Valdés, given that during the skirmishes prior to the Battle of Torata, Captain Blanco, in command of only 35 mounted hunters, he had fought against the enemy vanguard, killing an independence officer with his sword and dismounting from his horse in the middle of the crossfire to pick up his competitor's sword and hat.

For this distinguished action he was given a gift from the hands of Valdés himself and in the presence of the entire royalist division, a beautiful saber that had been taken from the Argentine commander Gregorio Aráoz de Lamadrid during a skirmish in Upper Peru and that Valdez kept to reward the first trait of extraordinary value.

When General Santa Cruz withdrew in defeat from Upper Peru, he led a party of scattered soldiers who joined the army of the patriotic leader José Miguel Lanza to fight under his orders in Alzuri against the forces of General Olañeta where, despite their courage, they were defeated by the best equipped royalist troops,[6] after this action he returned to Lima to join the united army of Bolívar being named commander of the third squadron of "Húsares del Perú" who, due to their brave participation in the Battle of Junín, in which Commander Soto was recognized for his courage in the official report, were renamed by the liberator as "Húsares de Junín", and that today constitute the presidential guard of Peru.

Under this situation of internal commotion, the invasion of the Peruvian army under the command of Agustín Gamarra took place, the objective of which was to force the departure of the Colombian troops from Bolivia given that they constituted a threat to Peru due to their rejection of the life presidency of Bolivar and problems bordering Gran Colombia was at the gates of a war with that country.

According to Francisco Burdett O'Connor in his Recuerdos, the events unfolded as follows: There were rumors, of course, that General Blanco had been assassinated by the orders of the captain of the National Guard and that the first Chief of First Battalion, Colonel José Ballivian.

This order was read to all the troops that made up the guard; and that same night, at midnight, the sentinel stationed in the corridor, sounded the alarm, and stated that groups of cholos were approaching the high wall in front of the convent.

[9]The Spanish historian Mariano Torrente, in his work dedicated to the Spanish-American wars of independence, referring in one of his passages to Blanco, would say: "it is certainly sensitive that such a commendable officer would have been successively sacrificed to the fury of those he freed".