Born in Canfranc, Aragon, and the son of the town's miller, Ezquerra was a Falangist and enthusiastically signed up for military service on the Nationalist side after the military coup of 18 July 1936. He fought on the fronts of Aragon, Madrid, Extremadura and Teruel, in the 7th "Bandera de Castilla" and in the 6th Granada Infantry Regiment. He was wounded in fighting around Huesca, commissioned as a "provisional second lieutenant" (alferez provisional) and ended the war as a provisional first lieutenant. He received several medals for valor. After the end of the war he was demobilised, and worked as a provincial chief of the "Obra Sindical de Artesania" union. He married Consuelo Reinoso and they had two daughters.