Glas was born in London, England, about 23 years ago. He was born into a relatively well off household and spent the early years of his childhood living quite lavishly. One day, when he was 10, he and his family left for a vacation in Greece. Somewhere along the way the plane they were on went off course and then went down due to mechanical faults; Glas was the only survivor. Glas awoke to the smell of smoke and an intense weight on his arm. When he finally managed to open his eyes he could see the burning wreckage of the plane and could see hints of charred corpses. Looking at his arm Glas saw that he was wedged under a piece of debris and couldn't move. Glas was trapped and there was fire approaching him, the only thing he could do was dislocate his own shoulder in order to free himself. The plane had gone down in a dense forest and Glas was forced to survive.
Glas remained undiscovered in that forest for 6 years and during that time he learned to fend for himself. Around the time of Glas' 16th birthday he stumbled across a campsite and waited there for the owners to return and once they did he was reintroduced to civilization. When Glas returned to the UK he was hounded by the media for his story of the last 6 years, which he refused to tell. After his return Glas didn't know what to do with himself. He eventually put his survival skills to use by joining the military and eventually became a mercenary. He ended up being on a job in Chernarus when it all went to shit.