Severus Snape is a character from J.K. Rowling's fictional book series Harry Potter. Snape is the Potions master at Hogwarts in the series. He is also known to be a Death Eater but after Voldemort started hunting Lily Evans, the woman Snape had loved since he was a child, he asked Albus Dumbledore to find a safe place for the Potters because he knew Voldemort wanted to kill their son, Harry Potter. As Dumbledore was not able to save the Potters, Snape's sorrow was real and extremely deep, he gained Dumbledore's trust. Snape was loyal to Dumbledore after this event. Snape killed Dumbledore in the sixth book because he has asked him to do that. Voldemort believed Snape killed him because Voldemort had planned Snape to do that.
Snape didn't kill himself after Lily's death only because of the green eyes he had loved that Lily's son had inherited from her. Just before Snape's death in the seventh book Snape asks Harry to do the last thing for him.
The last thing Snape's eyes ever saw were Lily's green eyes. Later, Harry Potter and Ginny Weasley named their youngest son after Albus Dumbledore and Severus Snape. Harry confesses to his son Albus Severus that Severus Snape was the bravest man he ever knew even though while still at school, Snape had been the teacher that Harry had hated the most because of Snape's bad behaviour towards Harry. Snape was so mean to Harry because of Harry's father, James Potter, that had bullied Snape while they were at Hogwarts. Snape was more than a cruel, heartless death eater but rather a brave and sincere victim to the perils of love in the reign of a power obsessed and heartless dictator.