Which fictional school subject did J.K. Rowling create Professor Remus Lupin to teach?

J.K. Rowling created Professor Remus Lupin as the Defence Against the Dark Arts teacher.

Remus Lupin teaches the subject during Harry’s third year at Hogwarts, in Harry Potter and the Prisoner of Azkaban. He is portrayed as an unusually effective and compassionate teacher, helping students confront dangerous magical creatures and giving Harry practical instruction in dealing with Dementors.

Lupin’s appointment fits a recurring pattern in the series: Defence Against the Dark Arts teachers do not remain in the post for long. His tenure ends after his werewolf identity becomes known to parents and school authorities. The character later returns as a member of the Order of the Phoenix.

Defence Against the Dark Arts is distinct from several neighboring Hogwarts subjects. Potions is taught by Severus Snape for much of the early series, Transfiguration by Minerva McGonagall, and Charms by Filius Flitwick. Lupin’s subject is therefore a specific teaching role, not a general description of his magic.