[Japanese Edition] Harry Potter and the ORDER of the PHOENIX [New Edition] 3 (Harry Potter Bunko) J. K. Rolling, Yuko Matsuoka

In response to Umbridge's refusal to teach practical skills, Dumbledore's Army ( DA ) was formed, with Harry acting as teacher! However, Headmaster Dumbledore left the School of Witchcraft and Wizardry when the powers that be intervened. Teachers disliked by Umbridge were fired and rebellious students were expelled.