When he tried to kill the baby Potter, Voldemort accidentally created anew horcrux. Harry Potter himself. Lily's love for his son protected himfrom the evil wizard, the curse struck Harry and killing was reflected, in part, the dark lord. A fragment of the seventh piece of Voldemort's soulwas in Harry (and thus it can communicate with snakes and enter the mind of Voldemort). The dark lord has become an almost nothing, requiring unicorn blood to live, he tried to steal the Philosopher's Stonein 1992 to compose herself. But it was not until 1995 that he made it back to human form (or nearly so, the soul apart so many times, not good for your appearance).