Albus Dumbledore-Headmaster of Hogwarts School of Witchcraft and Wizardry, leader of the Order of the Phoenix, discovered the twelve uses of dragon's blood.
Minerva McGonagall-Professor of Transfiguration at Hogwarts School of Witchcraft and Wizardry. Head of the Gryffindor House. Deputy Headmistress to Albus Dumbledore.
Severus Snape-Professor of Potions at Hogwarts School of Witchcraft and Wizardry, and later Professor of Defense Against the Dark Arts. Head of the Slytherin House, member of the Order of the Phoenix and double agent..???
Rubeus Hagrid-Keeper of Keys and Grounds at Hogwarts School of Witchcraft and Wizardry and Professor of Care of Magical Creatures. Member of the Order of the Phoenix and loyal to Albus Dumbledore.
Sybill Trelawney-Professor of Divination at Hogwarts School of Witchcraft and Wizardry. Made the true prophecy regarding Harry Potter and Lord Voldemort.
Quirinus Quirrell-Professor of Defense Against the Dark Arts at Hogwarts School of Witchcraft and Wizardry. Later, Harry discovered Quirrell was loyal to Lord Voldemort and aided his return to human form by allowing him to attach to his own body.
Gilderoy Lockhart-Professor of Defense Against the Dark Arts at Hogwarts School of Witchcraft and Wizardry. Professor, Author and recipient of the Order of Merlin, Third Class.