Sired by a father he never knew and raised by a woman who never cared, Osuin found himself born into a hard life in the Shallows. By the age of ten he had already been put to work in the fields, and even at that young age his size was apparent. Osuin found sold to Cerakian slavers at the age of twelve in order to resolve debts accrued by his mother. He'd not see her again.

He would not see Cerak Al'Thul either, as the ship would not make a departure. The Knights of Anathaeum, abhoring the taking of slaves, had been watching and made their intervention. Grateful to be saved, he refused to be taken back to his home; and so, the knights offered him a new home in Astenvale. Ever since, Osuin has heeded the new calling, and has served for twenty years as a member of their order thus far.