When does he appear? Harry Potter and the Prisoner of Azkaban
Howarts House: Gryffindor
Memorable traits: Reckless, brave and unfailingly loyal to his friends, with the ability to turn into a big black dog at will (he's an Animagus) and a passionate hatred of his purbelood family and their values. While Sirius was a generally kind man, and a loving godfather to Harry, Rowling also wasn't afraid to show his flaws, including his lack of compassion to house elf Kreacher, and his cruel treatment of Severus Snape during his school years.
9. Severus Snape
Who is he? A mass of contradictions, each one more compelling than the last - and a prime example of Rowling's belief in the redemptive power of love. Also Potions Master at Hogwarts (until he takes over as Defence Against the Dark Arts teacher in the sixth book).
When does he appear? Harry Potter and the Philospher's Stone.
Howarts House: Slytherin - but, as Dumbledore later noted, with the words "I sometimes think we sort too soon", his eventual bravery would have made him a fine Gryffindor, too.
Memorable traits: Being a truly terrifying teacher, and unfairly persecuting Harry, due to an ongoing grudge against Harry's long-dead father - but also risking his life to protect Harry, bravely betraying Voldemort and acting as an undercover spy, due to his ongoing unrequited love for Harry's long-dead mother. In other words, Snape is Complicated.
8. Harry Potter
Who is he? Only The Boy Who Lived. Magical baby who defeated the evil Lord Voldemort with nothing but a mother's love. Facially scarred. Lived under a staircase for most of his childhood.
When does he appear? Harry Potter and the Philosopher's Stone
Hogwarts House? Gryffindor. Although the Sorting Hat was unsure, giving Harry yet another neurosis to ponder on for the rest of his life.
Memorable traits: A propensity for moodiness. Other, more Gryffindor-y qualities include: Bravery. Acceptable levels of intelligence. A strong moral core. Loyalty, especially to his deceased parents. A powerful command of a Patronus and broomstick (sometimes simultaneously). Fond of the mercurial friendship of older men. Harry: possibly one of the least invigorating central characters of the entire series, but without him, we'd be scuppered.
7. Ron Weasley
Who is he? Harry Potter's best friend. Arachnophobe. Aspiring Quiddich player.
When does he appear? Harry Potter and the Philosopher's Stone
Hogwarts House? Gryffindor
Memorable traits: He may be gawky, tall and the comic relief in the trio of Harry, Ron and Hermione, but the youngest Weasley son has long proved his hidden depths. Fiercely loyal with tactical smarts that are often underrated, Ron puts up with Harry's mood swings and, let's face it, reluctant glory-hugging while remaining steadfast as the Boy Wizard's emotional prop. A telling moment happens early on, when Ron is shown matching the accomplishments of his brothers in the Mirror of Erised: he is a boy of simple ambitions but bold feeling.
6. Draco Malfoy
Who is he? Harry Potter's schoolboy nemesis. Unlikely object of fervent fan attraction.
When does he appear? Harry Potter and the Philosopher's Stone
Hogwarts House? Slytherin
Memorable traits: Slicked-back white blonde hair and snooty demeanour. Malfoy has inherited an unpleasant blood-racism from his father, Lucius, and repeatedly refers to Hermione as a "mudblood". For all of his affectations of dark magic, however, he is not wholly bad: he fails to complete the mission cruelly put upon him by Lord Voldemort, and comes to reject his youthful zeal later in life.
5. Neville Longbottom
Who is he? Harry's clumsy, inept classmate, who struggles with lessons (and general life skills) but eventually develops a talent for Herbology - and shows inspiring bravery at the Battle of Hogwarts.
When does he appear? Harry Potter and the Philospher's Stone
Howarts House: Gryffindor
Traits: Being plump, shy, and a bit rubbish at everything (except Herbology).But like all the best characters - and the best magical plants - Neville grows throughout the books.
The ultimate Neville moment: Pulling Gryffindor's sword from the Sorting Hat at the Battle of Hogwarts, and using it to kill Nagini
4. Luna Lovegood
Who is she? Endearingly eccentric Ravenclaw student and member of Dumbledore's army
When does she appear? Harry Potter and the Order of the Phoenix
Howarts House: Ravenclaw
Memorable traits: Being completely bonkers - and believing absolutely anything, no matter how unlikely and outlandish it might seem.
3. Hermione Grainger
Who is she? Muggle-born genius, frizzy of hair, unofficial patron saint of bossy girls everywhere.
When do we first meet her? Harry Potter and the Philosopher's Stone
Hogwarts House: Gryffindor
Memorable traits: Hermione's unashamed academia, self-belief in her brain and assertive nature became a rallying cry for the girls who read Harry Potter and had always been told to not be bossy. She is brave and brilliant, but is made all the more human by her quiet struggle to fit in. Her (initially) unrequited love for Ron is painful and poignant to discover, and those who have learned of her future can't help but feel her triumph is the most deserved of any of Rowling's creations.
2. Minerva McGonagall
Who is she? Head of Gryffindor House, Scottish (sometimes transfigurative) wildcat.
When do we first meet her? Harry Potter and the Philosopher's Stone
Hogwarts House: Gryffindor
Memorable traits: A fondness for tartan and Hermione Grainger. Beyond that, McGonagall is one of Rowling's best characters, rounded and forthright, she champions Harry as much as Dumbledore but with none of the saccharine mystique he can deploy.
The ultimate McGonagall moment? When she transfigures the statues on Hogwarts castle to attack the death eaters.
1. Albus Dumbledore
Who is he? Headmaster of Hogwarts, believed to be the most talented magician of his generation - and the only man Vodlemort ever feared.
First appearance: Harry Potter and the Philospher's Stone
Howarts House: Gryffindor
Memorable traits: Long beard, eccentric manner - and an enduring love for his favourite student, Harry. Late on in the book series, it is also revealed that Dumbledore had a tragic past. During his youth, he was swept away by the visions of his ambitious friend Grindelwald and planned to join him in his quest for "the greater good" - but later had a change of heart, after an argument with Grindelwald led to the death of Dumbledore's troubled sister, Ariana. While Dumbledore later defeated Grindelwald in a famous duel, his early mistakes left him chastened, and, despite repeated offers, he resolved to never seek a position of political power, preferring to remain at Hogwarts instead.
