One of Harry's father James Potter's closest friends. Sirius was wrongly convicted of telling Lord Voldemort the whereabouts of Harry's parents, so that the Dark Lord could murder them.

In Prisoner Of Azkaban, Sirius escapes from the prison and Harry and his friends get proof of his innocence. Sirius soon comes to signify the family Harry never had.

In the movie version of Goblet Of Fire, Sirius' role has been limited to one conversation.