Albus Dumbledore

"After all, to the well organized mind, death is but the next great adventure."

- Dumbledore to Harry Potter about death "Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?"

- Dumbledore to Harry Potter in Limbo "It is our choices, Harry, that show who we truly are, far more than our abilities"

- Dumbledore to Harry Potter about choices

Albus Percival Wilfruc Brian Dumbledore, was the Transfiguration Professor, and later Headmaster of Hogwarts School of Witchcraft and Wizardry. Professor Dumbledore also served as Supreme Mugwump of the International Confederation of Wizards (?–1995) and Chief Warlock of the Wizengamot (?–1995; 1996-1997). He was a half-blood wizard, the son of Percival and Kendra Dumbledore, and the elder brother of Aberforth and Ariana. His father died in Azkaban when Dumbledore was young, while his mother and sister were later accidentally killed. His early losses greatly affected him early on, even at his death, but in turn made him a better person. Albus Dumbledore was considered to be the most powerful wizard of his time. He was most famous for his defeat of Gellert Grindelwald, the discovery of the twelve uses of dragon's blood, and his work on alchemy with Nicolas Flamel.

It was through Dumbledore that resistance to the rise of Lord Voldemort was formed, as it was he who founded and led both the first and second Order of the Phoenix. Due to the fact that he had a keen mind and legendary power, Dumbledore became the only wizard that Voldemort ever feared. He was the wielder and the master of the Elder Wand from 1945 until 1997 and considered by many as the greatest Headmaster to ever grace Hogwarts. When Harry Potter arrived, Dumbledore took a personal interest in him and aided him many times during his years at Hogwarts.

Unfortunately, after coming into possession of one of Voldemort's Horcruxes, the cursed ring of Marvolo Gaunt, he became fatally cursed. As he was about to die, he planned his own death with Severus Snape. Though he was no longer alive at the time, it was through Dumbledore's machinations that Voldemort was ultimately defeated and peace restored to the wizarding world. He is the only Headmaster that was laid to rest at Hogwarts. Albus Dumbledore's portrait still remains at Hogwarts.

Powers
Dumbledore was an incredibly powerful and knowledgeable sorcerer. He was a star at Hogwarts, and his accomplishments were only rivalled by that of Lord Voldemort. He was adept at the Patronus Charm - his took the form of a phoenix - and was skilled enough to perfect the Patronus so that it could actually speak. In addition, Dumbledore was extremely talented in pyrokinetic magic - his signature spell was the utility of fire. This ability was so advanced that he could create a huge firestorm, in spite of the fact that he was currently hallucinating and also heavily incapacitated by a poison. He was also an incredibly proficient duellist, able to remain on par with the extremely powerful Lord Voldemort, but also able to defeat the Elder-Wand-wielding Gellert Grindelwald, despite the latter having the ultimate advantages.

Trivia

 * In the Harry Potter films, Dumbledore was played by the late Richard Harris in The Philosopher's Stone and The Chamber of Secrets, whilst Michael Gambon played him in the remaining films after Harris's death.
 * He is spoofed in The Grim Adventures of Billy & Mandy as Dean Toadblatt.