Gregory's parents, Zack and Luanne, were both separately among the founders of Kimrin, in 879. Zack became one of the earliest members of the Kimrin police department, recruited by Poss Primus. Luanne got a job as a farmhand on the farm owned by Poss's parents, which is where she and Zack first met, in 883. They married in 885, and in 887, they had Gregory, their first and only child.
When Gregory was 10, his family were among the founders of Near Port, where Zack became a deputy chief of the new village's police department, and Luanne got a job on another farm. When Gregory was 14, his parents both joined the newly organized army of Near Port (Zack as a sergeant, Luanne as a soldier). Two years later, they fought in several battles of the Coming of the Order. Several days prior to the Battle of Near Port, Zack was promoted to lieutenant. However, during that battle, both he and Luanne were killed by Protestant forces. Gregory was now an orphan, with no other family to turn to, and was anxious to avenge his parents' deaths, so he applied to join the army. It was then, at 16 years of age, that he was taken under the wing of General Poss Primus, who had for the first ten years Gregory's life been like an uncle to him. Hoping to keep Gregory out of battle, Poss made him his aide-de-camp. It was for this reason that when the surname law was later passed, in 904, Gregory chose the name 'deCamp.'
After the war, Gregory continued in his position as Poss's adjutant. When Poss was promoted to marshal in 905, he promoted Gregory to sergeant. Over the years, the two developed a close friendship, though they maintained a professional working relationship. In addition to his office duties, Gregory received regular combat training, at which he excelled. In 909, he was promoted to lieutenant.
In 912, Gregory distinguished himself in battle during the Chaos War, and after the war was under consideration for promotion to captain. However, he was killed while defending Poss against an unexpected attack by the fugitives Demos Royal and René Deadzone. Poss later reported that Gregory's body was incinerated by the Sorreter's attack.