Harold is one of, if not the most unique denizens of the wasteland. Born not-long before the Great War, he has survived by being in a Vault. Not long after leaving, he began to amass a small fortune as a trader. During his ventures in the wastes, he has met several influencial and important personalities in the wastes, whilst bearing witness to plethora of crucial events. At some point, Harold decided to start running his own caravan business, quickly rising to success as a caravan master in the beginning years of the Hub. However, a hefty cost slowly amassed itself as attacks from gangers, scavengers and mutants continued to pile on. Eventually, having had enough of the attacks, Harold financed one of the first adventuring parties together with a prominent, yet mysterious scientist from the Hub, with the goal in mind of finding the source of the attackers. The expedition went far-north, breaching through hordes of mutants before arriving in the Mariposa Military Base. Most of the expedition, weakened and injured after pushing through the mutant hordes, eventually find their way inside the base, of which Harold and Richard Grey would breach into the very core of the complex, where the FEV vats were located. Things went south as a robotic crane crashed into the two, throwing Richard into one of the vats, leaving Harold badly injured, him eventually losing consciousness. Many days later, Harold woke up to find himself out in the wasteland, in the middle of a FEV-induced transformation, caused by prior handling of contaminated materials, Harold now closely resembling a ghoul. Few days later, a group of traders stumble across Harold, and bring him back to the Hub. His transformation into a mutant caused most of his employees and partners to turn away from him, leaving him a beggar in the Hub's streets for a considerable amounts of time.
At some point in time, Harold has decided to move on, setting himself for finding the old Poseidon Oil reactor number 5. At some point, he's apprehended by Vault City patrols while on his search, and later incarcerated.