Shortly before Lily Evans was murdered by Lord Voldemort, Snape changed sides and became a member of the Order of the Phoenix as well as a double agent during the Second Wizarding War.With tremendous difficulty, Snape prevented Lord Voldemort from learning the truth about his loyalties.The only child of Muggle lowlife Tobias Snape and Gobstones witch Eileen Snape , Severus was raised in the Muggle dwelling of Spinner's End, which was in close proximity to the home of the Evans family, though in a poorer area.He met Lily and Petunia Evans when he was nine and fell deeply in love with Lily, becoming a close friend of hers.You are fighting that which is unfixed, mutating, indestructible." of the Hogwarts School of Witchcraft and Wizardry as well as a member of the Order of the Phoenix and a Death Eater.His double life played an extremely important role in both of the Wizarding Wars against Voldemort.Severus started at Hogwarts with Lily in 1971, where he was Sorted into Slytherin House.This put him in the same year as Lily but unfortunately for him in rival houses.
After watching her for some time, Severus noticed her evident magical abilities and began making friendly overtures.
It is implied that Severus was friendless and uncared for by his parents.
This lack of care largely shaped Severus's bitter disposition and cruel behaviour later in his life.
Severus became the immediate enemy of James Potter and Sirius Black and was a frequent victim of their bullying.
This led him to be irritable towards James's son Harry when he was a professor.