|Romulus John Lupin|
Romulus John Lupin was the father of Remus Lupin. At some point during the 1960s or early 1970s, he offended the werewolf Fenrir Greyback, which lead Greyback to bite and infect his young son in revenge, which is how Remus Lupin became a werewolf.
Along with his wife, Mr. Lupin tried all manner of treatments for his son's lycanthropy, but in those days, before Damocles's invention of the Wolfsbane Potion, there were no cures that actually worked. He and his wife worried that their son would not be able to attend Hogwarts School of Witchcraft and Wizardry, due to his condition, but Albus Dumbledore made a special provision for the boy.