Harold is a very private person, so little is known about his life before he became a Vampire.
He was born in Ireland, had a wife and children. All of it was lost, when he was taken from his home and sold into slavery.
(Dilios Note: He doesn’t talk about it, and the only person who knows everything that happened in those years is his Mate, John. His Sires are close seconds.)
Harold realized he had an opportunity to escape when Nico and Arthur showed up as slaves.
It was during the raid and escape that he was injured, leading to the two Vampires Turning him. (Dilios Note: It is the rarity, actually this is the only case I know of, where two Vampires were involved in Turning someone).