Ernest joined the Luxembourg Army in July 1945 and was attached to the Ist Battalion stationed in Walferdange. In September 1945, he was transferred to the Corps de la Garde. He re-enlisted in July 1946.

As a Sergent, Ernest served as section leader in the second Luxembourg contingent. On 11 September 1952, he was wounded during an enemy offensive, but refused to leave the battlefield. Despite his exemplary attitude, the injuries he sustained disabled him from fighting on the frontline, which caused him on a later stage to be reattached to the battalion as a medic. 

Paul Lamesch, Nicolas Kremer and Erny left Korea on 3 February 1954. Their service of 692 days made them part of the very few veterans, who extended their contractual term of 365 days. Back in Luxembourg, Ernest continued his military career and was promoted to Sergent-Chef tit. in January 1956.

On 1 February 1959, he was involved in a car accident on the Passerelle in Luxembourg City, when he crashed into a tramway. Ernest suffered fatal injuries and was transported to St. Joseph's Hospital, where he tragically died at the age of 30.