Snape 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.
In 1971 he began his first term at Hogwarts where he was Sorted into Slytherin House. This put him in the same year as Lily but unfortunately for him, in rival houses. Severus became the immediate enemy of James Potter and Sirius Black and was a frequent victim of their bullying.
Snape developed a passion for the Dark Arts at a young age, which increased as his desire for revenge grew stronger. He became involved with the bullies in Slytherin House, many of whom were pure-blood supremacists. This put his friendship with Lily, a Muggle-born, under great strain, until it was eventually broken in their fifth year.