HEAΓT OF UNCEΓTAINTγ Severus Snape of the Harry Potter series

corner hrouded in mystery until and even after the end is Snape's life. The following article attempts to piece together a concrete journey through the life of one Severus Snape, from his unhappy childhood to his years at Hogwarts as both student and professor, and to the short time after he leaves Hogwarts. For convenience of quickest reading, I will resort to the unsavoury but succinct use of bullet points.

Severus Snape is born to Witch Eileen Prince and Muggle Tobias Snape. The couple is poor in both wealth and love for their son.
Snape begins spying on two Muggle girls, Lily and Petunia Evans, when he sees the magical potential of the first.
Snape reveals himself to the sisters but is rebuffed when he insults Petunia for being a Muggle.
Snape manages to befriend Lily, but she becomes angry with him when he sets a branch to fall on her sister's head.
Snape and Lily receive letters to attend Hogwarts School of Witchcraft and Wizardry, while Petunia doesn't.

Almost when he arrives at Hogwarts, Snape is picked on by James Potter and Sirius Black.
Snape is sorted into Slytherin while Lily is sorted into Gryffindor. Despite the differences in house, the two remain friends.
Snape becomes known for being an outcast, beguiled by the Dark Arts, and an easy target. He befriends those students who will become Death Eaters later on in life, much to the unhappiness of Lily.
Sirius Black plays a trick on Snape, almost leading to his death at the hands of a transformed Remus Lupin. He is saved by his mortal enemy James Potter.
After their O.W.L.'s in fifth year, James Potter uses Snape's own spell against him in front of a group of students. Lily comes to his defense, but in his humiliation Snape calls her the worst name possible: "Mudblood". This destroys his friendship with Lily.

Severus Snape joins the Death Eaters.
Snape overhears a portion of Trelawny's prophecy about Voldemort, and before hearing it in full, runs off to report to Voldemort.
This leads Voldemort to the Potters.
Frantic in worry, Snape risks his life to seek out Dumbledore for his help in protecting Lily. In payment, he turns spy for Dumbledore.
Despite Dumbledore's best efforts, Lily and her family, minus their baby son Harry, are killed by Voldemort. Snape is in hysterics. Dumbledore suggests he take on the role lost with Lily at her death: that of protector of her son, Harry.
During Karkaroff's trial, Snape is mentioned as a Death Eater, but Dumbledore reveals that Snape had worked as a double-agent against Voldemort during the end of the war.

Snape, at Dumbledore's request, takes on the position of Potions Master and Head of Slytherin House at Hogwarts.

Snape and the other teachers place protective spells over the door leading to the hiding place of the Philosopher's Stone.
Snape mistrusts the new Defence Against the Dark Arts professor Quirrell. Students believe he only wants Quirrell's job.
During the troll incident, Snape heads to the third floor where the Philosopher's Stone is being stored to make sure that the safeguards haven't been breached. He's injured by the three-headed dog Fluffy in the process.
Harry notices Snape is limping, and then stumbled upon Filch bandaging Snape's leg in his office.
During the Quidditch match, Snape prevents Quirrell from harming Harry. Hermione, thinking Snape is up to no good, she distracts him while incidentally knocking aside Quirrell, the true culprit.
After this incident, Snape trails Harry closely, much to his bemusement.
Snape, believing him to be responsible for bringing the troll to Hogwarts, confronts Quirrell about his loyalties.

Snape catches Harry and Ron sneaking into Hogwarts after crashing Mr. Weasley's car into the Whomping Willow.
To his dismay, Dumbledore doesn't suspend them.
Snape sends the Gryffindor Quidditch team a note relating the fact that Draco Malfoy is now seeker of the Slytherin team.
Snape is amused by the petrified Mrs. Norris.
Snape questions Ron, Hermione and Harry about their being in the corridor where Mrs. Norris was petrified. He believes they're hiding some truth.
Lockhart insults Snape by suggesting his own abilities as a potions-maker.
During the Duelling Club, Snape and Lockhart duel, with Snape emerging victor.
Malfoy gushes to Snape about how he should be Headmaster.
Snape and the other teachers bullies Lockhart into taking on the task of destroying the Basilisk.
Snape had unwittingly helped Harry by teaching him the Expelliarmus spell which un-arms Lockhart, thereby preventing him from using a Memory Charm on Harry and Ron.

Snape bullies Neville in Potions Class.
In Defence Against the Dark Arts, Neville defeats the Boggart by imagining it as Snape in his grandmother's clothes.
Thereafter, Snape is in a bad mood, obviously having heard about the incident. Snape also begins to keep a closer eye on Lupin.
Snape expresses his concern to Dumbledore about Lupin's possibly helping Sirius Black enter Hogwarts; Dumbledore puts him in his place.
During the first full moon, Snape temporarily takes over for Lupin as teacher of Defence Against the Dark Arts. In class, he hints at the reasons for Lupin's absence by having the students study werewolves.
Snape nearly catches Harry on his way through the secret passage to Hogsmeade; he doesn’t seem to know how to work the one-eyed witch statue, but realises it’s the ticket.
Snape catches Harry in the corridors at night. Snape tells Harry about how his father and his friends played a nasty trick on him when they were young. Snape confiscates the Marauder’s Map and attempts to access it; Moody, Wormtail, Padfoot and Prongs tell him off by way of the map. Snape summons Lupin, who covers for Harry, much to Snape’s aggravation.
Snape catches the trio, Lupin and Sirius in the Shrieking Shack. He believes Lupin has been aiding Sirius. The trio triple-team Snape and knock him out.
Snape is congratulated by the Minister of Magic, even offered Order of Merlin First/Second Class; Snape covers for the children by explaining they were Confunded by Sirius, but not without remarking on Dumbledore’s favouritism of Harry nor without insisting on due punishment because of the danger Harry put himself and the rest in.
Snape argues with Dumbledore over Sirius' innocence, irritating the older man.
Snape is furious when Sirius is found to have escaped, and blames it on Harry.
Snape tells the Slytherins that Lupin is a werewolf, and he’s swiftly sent packing.

On first arriving at Hogwarts, Made-Eye Moody (Crouch Jr. in disguise) insinuates Snape is a Death Eater.
When Karkaroff complains about Harry having added his vote to the Goblet of Fire, Snape defends Dumbledore, though not without insulting Harry.
Snape insults Hermione about her lengthened teeth, prompting Harry to imagine casting Crucio on him.
During the Yule Ball, Karkaroff talks in fear to Snape of the Dark Lord's return, urging him flee. Snape, however, remains stalwart.
Crouch Jr. searches through Snape's Office during the night.
The next day, Snape is complaining to the disguised Crouch Jr. about the robbery when the Dark Mark on his arm goes off.
Snape and Moody face-off in the corridor late at night, Snape believing a hidden Harry to be out and about; Moody doesn't give in, forcing Snape to head back to his quarters.
In class, Snape catches the trio in conversation about Rita Skeeter’s article about Hermione and separates them, but only after reading it out with fruitful commentation.
Snape insists Harry was the one who broke into his office the other night, and threatens him with the Veritaserum.
Karkaroff enters the classroom and approaches Snape in relative privacy; he demands Snape leave for a private discussion, and shows him his arm, which infuriates Snape (apparently Karkaroff was showing his inflamed Dark Mark and Snape was worried one of the students would see).
Later, Snape thwarts Harry’s efforts to find Dumbledore, much to his personal amusement.
Snape shows Fudge his Dark Mark to prove the return of Voldemort.
Dumbledore reinstates the Order of the Phoenix; Snape and Sirius are barely able to set aside their hatred to shake hands for him.
Dumbledore sends Snape off to act as double-agent once more.

Throughout the previous summer, Snape regularly reports back to Dumbledore and the Order at Grimmauld Place.
After Christmas, Snape tells Harry Dumbledore has requested him to teach Harry Occlumency.
While there, Sirius and Snape nearly start a duel, and Harry is forced to intervene.
Back at school, Harry meets with Snape for "remedial Potions". Snape had removed some of his memories into the Pensieve prior to the session. During the session, Harry barely tries to focus, testing Snape's irritability.
During their next session, Harry questions Snape on his loyalty to Voldemort, but Snape is unable to reply given the interruption of Trelawny's screams from above.
One session later, Snape leaves for a moment to speak with Draco Malfoy, and Harry takes the opportunity to look into the memories Snape had removed prior to the lesson. He witnesses his father and his friends bullying Snape in front of the school, while his mother defends Snape. Present-day Snape pulls him out of the memory and kicks him out of his office, refusing any more Occlumency lessons.
Harry begins to feel sorry for Snape.
Umbridge orders Snape to make him Veritiserum, but he refuses, citing the time it would take to make it - and saving Harry from revealing truths best kept secret.
Harry warns Snape that “Padfoot” is being held hostage; Snape feigns ignorance, but afterward sends the message to Dumbledore.

Bellatrix and Narcissa meet with Snape in secret at his home in Spinner's End. Snape and Bellatrix argue over his true loyalties. Narcissa and Snape make an Unbreakable Vow, the conditions of which will protect her son Draco from harm.
Dumbledore attempts to use Marvolo's Ring, and had it not been for Snape's speedy response, he would have died from its curse. Snape attempts to stem the damage, but warns Dumbledore he has less than a year to live. Dumbledore talks to Snape of Voldemort’s plan to have Draco murder him; he has Snape promise not only to protect the students in Hogwarts after his death, but to do the deed himself when the time came. With great hesitation, Snape agrees.
At the start of the Hogwarts year, Snape is instated as Defence Against the Dark Arts professor.
Harry discovers the Half-Blood Prince. Using his knowledge, Harry becomes a top Potions student.
When Malfoy “gatecrashes” Slughorn’s Christmas bash, Snape appears almost frightened; almost immediately takes Draco away from the party for a chat. Snape asks Draco to confide in him, given that he has made an Unbreakable Vow to protect him, but Draco refuses; Snape then attempts Legilimency on Draco, who blocks with Occlumency.
Snape begins to interrogate students in his house. When Dumbledore finds out he is not amused. Hagrid overhears their ensuing argument.
Harry uses the Sectumsempra spell against Draco, and the latter is only healed after Snape applies three recitals of the counter-curse. Snape takes Draco to the infirmary and asks Harry to wait for him; when he returns, he performs Legilimency on Harry and discovers that he learned the spell from the Half-Blood Prince’s Potions textbook. When Harry hands over Ron’s copy of the textbook, Snape sees through the ruse and sentences him to detention, which includes Harry missing the last Quidditch game of the season.
For his first detention, Snape has Harry sort and re-label recorded past misdeeds, including those of his father and his father’s friends.
After Dumbledore has taken Voldemort’s potion which had hidden the locket Horcrux, he asks Harry to retrieve Snape, and only Snape.
On the Tower, Dumbledore asks Snape to kill him.
Snape escapes Hogwarts with the other Death Eaters, Harry hot on his heels; Snape reveals he is the Half-Blood Prince.

Dumbledore’s portrait tells Snape to Confund Mundungus Fletcher, and it is he who passes on the ploy of the multiple Harry Potter decoys.
Snape tells Voldemort that Harry will be escaping his relatives at an earlier date; Voldemort trusts him on this. On the night of, the Death Eaters attack the patrol leading Harry away. Snape accidentally curses off George Weasley's ear.
Snape is instated as Hogwarts Headmaster.
Dirk, Ted and Dean that Ginny and others attempted to steal Gryffindor’s sword - which, it turns out, is a fake - from Snape’s office. Snape merely sends them on a detention with Hagrid in the Forbidden Forest.
Following this incident, Snape is at the mercy of a small band of students, of which Harry and Hermione are certain Ginny is heading.
Snape, on Portrait Dumbledore’s orders, takes the Sword of Gryffindor and heads for the forest. He casts his doe Patronus and leads Harry to the Sword of Gryffindor, which he'd thrown into a pond in the forest beside where Harry is secretly in hiding.
The war imminent, Snape and McGonagall engage in an impressive duel filled with slicing moves, shield charms, wreaths of fire and black snake. When Flitwick arrives, Snape escapes by jumping through the window and transforming into a bat to fly away.
In the Shrieking Shack, Voldemort asks Lucius Malfoy to find Snape. When he arrives, Snape asks Voldemort to let him find Harry; Voldemort instead demands Snape tell him why the Elder Wand refuses to work powerful magic for him. He informs Snape that he must kill him in order to become master of the Elder Wand. And so he does.
With his dying breath, Snape pulls out the last of his memories and gives them to Harry. He looks into Harry's eyes, seeing the eyes of the love of his life, Lily.
Harry learns the entire truth, at last.
Harry, in their last duel, informs Voldemort that Snape was Dumbledore’s man until the end.

Harry names his son Albus Severus.