Senator Alister Breckenridge (b. January 21, 1921) was the Headmaster of Ilvermorny School of Witchcraft and Wizardry (1971 – 2012) for a period of forty-one years, during which time he also taught Magical Politics at the school. He was a half-blood wizard, instrumental in the repeal of Rappaport's Law. Born in Albany, New York, Alister received his education at Ilvermorny School, where he was sorted into Pukwudgie.
He was a spectator to the rise and fall of the Dark Lord Voldemort, and was particularly adamant about keeping the Dark Lord's influence out and away from Ilvermorny and the magical United States. As a result, he was in regular correspondence with Albus Dumbledore, the Headmaster of Hogwarts School of Witchcraft and Wizardry before his death, in order to keep an eye on Voldemort's movements in Europe and abroad. Upon Dumbledore's demise, he was unable to attend his old friend's funeral, however, he held a memorial in memory of the great Hogwarts Headmaster on the grounds of Ilvermorny.
Following his retirement as Headmaster of the school in 2012, Alister became a Senator in the Magical Congress of the United States of America, hoping to continue his work in ensuring the liberty of American witches and wizards, and ridding the influence of dark magic from the North American continent.