Born in Vancouver, Ambrose moved to Quebec city at 15 years old. At the age of 19, he entered in the reserve of the marines corps. After 2 years in the reserve, he realized that knowing so many languages could be very useful for the UNSC. In early 2605 with the rank of Sergeant Major, gained during his time in the reserve, he fully entered in the Marines Corps hoping to help humanity in the reconstruction, but only to realize that by 2616, a real war was about to start.