There was the first confrontation between the liberals and the Carlist army in the Valley of Berrotza of Navarra. Zumalacárregui threatened to fuse everyone who gave his neck to the enemy, and received a few tired workouts that beat the liberals with 350 casualties.

The newly ruled Zumalacárregui continued to reorganize his men, to form an army of thousands of people, and the unforeseen blows, practicing the guerrilla war, in 1835 controlled almost all Hego Euskal Herria.

When the war broke out, there were 18,000 liberal soldiers in Basque Country to deal with the Carlist rebellion, and in 1835 more than 120,000.