- Fred Weasley: "He never managed to get all the words out, due to the fact that we forced him head-first into that Vanishing Cabinet on the first floor."
- Hermione Granger: "But you’ll get into terrible trouble!"
- Fred Weasley: "Not until Montague reappears, and that could take weeks, I dunno where we sent him."
- — Fred Weasley on him and his twin George pushing Montague into the Vanishing Cabinet in 1996.
Graham Montague was a Slytherin student who attended Hogwarts School of Witchcraft and Wizardry in the 1990s. He played Chaser on the Slytherin Quidditch team from 1993 to 1996 and was a member of the Inquisitorial Squad. Montague was heavily built and had large, hairy forearms.
1993-1994 Quidditch seasonEdit
Montague played in the final match between Slytherin and Gryffindor in 1994. When Gryffindor Chaser Katie Bell got possession of the Quaffle, Montague flew in front of her, but, instead of taking the ball, he grabbed her head. Although Katie was able to keep from falling off her broom, she dropped the Quaffle. Madam Hooch scolded Montague and awarded a penalty to Katie.
1995-1996 Quidditch seasonEdit
At the beginning of the 1995-1996 Quidditch season, Montague was made Captain of the Slytherin Quidditch team, replacing Marcus Flint. He chose Vincent Crabbe and Gregory Goyle to be the team's new Beaters.
Vanishing Cabinet incidentEdit
Montague joined the Inquisitorial Squad in April of 1996. During morning break on his first day as a member, he tried to take House points from Fred and George Weasley, but the twins shoved him into the Vanishing Cabinet before he could finish speaking. While trapped inside, Montague could occasionally hear goings-on at Hogwarts, as well as at Borgin and Burkes, where the Cabinet's counterpart was located. He managed to Apparate out the next day, despite never having obtained an Apparition licence, but ended up lodged inside a toilet on the fourth floor.
The Apparition nearly proved fatal to Montague. He was left in a disoriented state for weeks afterwards. In May, his parents, Mr. and Mrs. Montague, came to the school, looking furious. Harry Potter, Ron Weasley, and Hermione Granger watched the couple arrive, and Hermione suggested that they should tell Madam Pomfrey what had happened to Montague, in case it would help her treat him. However, both Ron and Harry dismissed this idea, so Hermione apparently let the matter drop. Several weeks later, during the O.W.L. exams in June, Harry went to the hospital wing, where he saw Madam Pomfrey spoon-feeding a vivid blue potion to Montague.
Montague eventually told his story to others, including Draco Malfoy, who was the only one to reach the conclusion that there was a connection between the Cabinet at Hogwarts and the Cabinet at Borgin and Burkes. This knowledge gave Draco the means to allow Death Eaters to enter the school the following year.
After Hogwarts, Montangue became romantically involved with a former colleague of Slytherin, and together they had a daughter named Isla. But coexistence was difficult after the birth of the girl and the two divorced .