~Potions Masters at Hogwarts School of Witchcraft and Wizardry~
Potions master is the title given to the Potions Professor at Hogwarts School of Witchcraft and Wizardry. They are in charge of teaching their subject to the students of Hogwarts in a classroom in the Dungeons, and they own an office, described as a "water closet", nearby.
Horace Slughorn (1920-1981)
Harry Potter: "My mother..."
Horace Slughorn: "You shouldn't have favourites as a teacher, of course, but she was one of mine."
— Professor Slughorn talking to Harry Potter.
Around 1920, a wizard named Horace Slughorn, who had previously studied at the school as a Slytherin, arrived at Hogwarts School of Witchcraft and Wizardry and was employed as Potions master. The Headmaster, and Slughorn's employer, was Professor Armando Dippet, who gave him the Potions master's office in the dungeons, though Slughorn hated it and described it as a "water-closet." At some point, he was also made Head of Slytherin House.Slughorn was described as a good teacher, but chose favourites out of the classes that he taught, sometimes for their ambition or their brains, sometimes for their charm or their talent, and he had an uncanny knack for choosing those who would go on to become outstanding in their various fields. Horace formed a club named the "Slug Club", of which his favourites were members with himself at the centre, making introductions, forging useful contacts between members, and always reaping some kind of benefit in return. Among them were Tom Riddle, Gwenog Jones, Ambrosius Flume, Dirk Cresswell, Lucius Malfoy and, one of his absolute favourites, Lily Evans.
"Cruel, sarcastic and disliked by everybody except the students in his own house (Slytherin), Snape taught Potions."
—A description of Severus Snape.
Albus Dumbledore, the new Headmaster, hired Severus Snape, one of Slughorn's ex-pupils. Snape became both Potions master and Head of Slytherin House, and took ownership of his predecessor's office and the Potions Classroom.Professor Snape was a ruthless disciplinarian, with little patience for foolishness, yet effective in his job and well respected by other professors. His deep understanding of potion brewing, as shown by his expert concoction of Wolfsbane Potion in 1993, transformed the knowledge of potions from mere chemistry to an art. But in 1996, Snape was granted his original wish and was made Professor of Defence Against the Dark Arts, leaving the space of Potions master to be filled.
The return of Horace Slughorn
"We are pleased to welcome a new member of our staff this year. Professor Slughorn is a former colleague of mine who has agreed to resume his old post of Potions master."
—Albus Dumbledore at the Welcoming Feast of 1996
Before the term of 1996, Albus Dumbledore, with the help of Harry Potter, persuaded Slughorn to come out of retirement and return to the school while Professor Snape became Defence Against the Dark Arts teacher. However, Slughorn insisted that his salary be increased and that he be given the office that once belonged to Galatea Merrythought instead of the one in the dungeons, which Snape continued to own. Slughorn was quick to reform the Slug Club with new members, including Melinda Bobbin, Flora and Hestia Carrow, Blaise Zabini, Hermione Granger, Ginny Weasley and, of course, Harry Potter.Slughorn was described as a much better teacher than his predecessor, Severus Snape. During the first lesson of the year he awarded Felix Felicis, also known as "Liquid Luck", to the brewer of the best Draught of Living Death . The potion went to Harry Potter, whom Slughorn thought had inherited his mother's talent but who, in fact, had copied notes written in Severus Snape's copy of Advanced Potion-Making.