 At the start of the War of the Pacific, he was commissioned as second in command of the regiment "Esmeralda" when it was created after the division of the older "Carampangue" in May 1879.Serving in this position, Holley fought in the Battle of Tacna.He was promoted to commander of the regiment when its prior commander, Santiago Amengual, was named chief of the First Division in the Lima Campaign.