|"Well, I think we should put it back in order for them, don't you?"|
- "Filthy half-breeds! Beasts! Uncontrolled animals!"
- —Dolores Umbridge insulting a herd of angry centaurs[src]
The conflict began as a result of Ministry of Magic bureaucrat Dolores Umbridge (Senior Undersecretary to the Minister for Magic, Defence Against the Dark Arts teacher, Hogwarts High Inquisitor, and Headmistress of Hogwarts School) angering a herd of centaurs in the forest after being led there by two students from the school, Harry Potter and Hermione Granger on the pretence of showing her a "secret weapon" to be used against the Ministry being developed by Albus Dumbledore and the Order of the Phoenix.
Senior Undersecretary to the Minister for Magic Dolores Umbridge was appointed the Defence Against the Dark Arts teacher at Hogwarts School by the Ministry of Magic, as a means to spy on Dumbledore and his staff. As the teacher, she taught the students purely theory of defensive spells and not the real thing to destroy any chance that Dumbledore would have the students "trained to in combat" to take on the Ministry.
When Harry spoke up about seeing Lord Voldemort return, she severely punished him in detentions where he would be made to write with a Black Quill; that is, he would write in his own blood while the words were carved into the back of his hand. Despite this, Harry, Ron, and Hermione found strength within. They formed the secret Defence Against the Dark Arts group known as Dumbledore's Army, lead and taught by Harry. The goal was to prepare the students that wished to join for the outside world and the dangers that waited, right under Umbridge's nose. A large number of students joined the group and helped the trio in opposing Umbridge.
Umbridge's reign at Hogwarts
Umbridge began to expand her power by means of becoming Hogwarts High Inquisitor, where she had the ability to inspect and fire other teachers, and, after Dumbledore was forced to flee by taking credit for Dumbledore's Army when it was discovered, Headmistress of the school. With enormous power over the teachers, students, and the whole school, Umbridge fired Sybill Trelawney and tried to fire Rubeus Hagrid at night so as not to make a scene, a skirmish that resulted in Minerva McGonagall being hit with four Stunning spells in the chest when she went to help him. Umbridge was held in contempt by most of the students, except for a select few who became her Inquisitorial Squad, and by most of the teachers as well.
Harry was given a vision (planted by Voldemort as a trick) of his godfather, Sirius Black, being tortured by Lord Voldemort. Desperate to save him at the Department of Mysteries where he believed him to be captured, Harry first decided to check to see if Sirius was indeed held captive by using the Floo Network to visit 12 Grimmauld Place. The only Floo Network fireplace not under surveillance, however, was in Umbridge's office, and so he broke in using Sirius Black's knife while his friends were stationed as lookouts. He visited Grimmauld Place and was lied to be Kreacher, who said that Sirius was indeed at the Department of Mysteries (when he was really upstairs), but before Harry could react he was caught by Umbridge.
While Umbridge pulled him out of the fireplace and grabbed him by the hair, his friends and fellow D.A. members: Hermione Granger, Ron Weasley, Ginny Weasley, Neville Longbottom, and Luna Lovegood were held in her office by Inquisitorial Squad members.
When Harry refused to tell her what he had been doing, Umbridge first attempted to dose him with Veritaserum, but Professor Snape told her he had no more. She then claimed that the Cruciatus Curse might "loosen his tongue", responding that "What Cornelius doesn't know won't hurt him" when Hermione said the curse was illegal. Hermione then spoke up, pretending to be revealing who Harry was contacting, and tricked Umbridge into following her and Harry into the Forbidden Forest in search of an alleged "secret weapon" of the Order of the Phoenix.
- "Over the plunging, many-coloured backs and heads of the centaurs Harry saw Umbridge being borne away through the trees by Bane, still screaming nonstop; her voice grew fainter and fainter until they could no longer hear it over the trampling of hooves surrounding them."
- —Description of Dolores Umbridge being dragged away by the centaurs[src]
In the forest, Harry wasn't sure if Hermione had a plan or if she was making it up as she went along. Hermione made sure to make a lot of noise, as she wanted to be overheard. Soon the party was confronted by a herd of centaurs. Umbridge, though frightened, shamelessly insulted the centaurs with racial slurs and her wizarding arrogance, calling them "filthy half-breeds" and "creatures of near-human intelligence".
When the centaurs made threatening moves, Umbridge cast Incarcerous on the centaur Magorian, strangling him with ropes. The centaur Bane then picked her up and carried her away deeper into the forest screaming (what happened to her beyond that, during her time with the Centaur herd until she was rescued, is unknown). When Harry dived to pick up her wand, it was snapped in half when one of the centaurs stepped on it.
As the centaurs turned on the children, Hermione protested, saying that centaurs did not hurt foals (young humans) and that they meant no harm, unlike Umbridge, and were not from the Ministry of Magic like her. Hermione accidentally insulted the centaurs by saying that they had wanted the centaurs to drive Umbridge off for them, as the centaurs took this as wizards thinking that centaurs existed to do their bidding.
The centaurs, deciding that they were arrogant wizards as well and that Harry was not a foal but nearing manhood, prepared to attack them but then Grawp, Rubeus Hagrid's Giant half-brother, arrived. The centaurs attacked him instead, shooting him with arrows in the face. Grawp chased away the centaurs, howling with pain, as blood from his face poured down on Harry and Hermione.
Harry and Hermione were joined in the forest by Ron, Ginny, Neville, and Luna, who escaped the Inquisitorial Squad's capture with a combination of hexes, jinxes, and a particularly good Bat-Bogey Hex from Ginny. The group decided to use Thestrals to fly to the Ministry of Magic in London (attracting them because Harry and Hermione were covered in Grawp's blood). In the Ministry of Magic, they navigated themselves down to the Department of Mysteries, only to discover that it had been a trick and that Sirius wasn't there. Instead, the Death Eaters were waiting for them for Harry to give them a prophecy Voldemort desired, and the Battle of the Department of Mysteries began.
- Horace Slughorn: "I might have been in hiding, but some funny rumours have reached me since Dolores Umbridge left! If that's how you treat teachers these days —"
- Albus Dumbledore: "Professor Umbridge ran afoul of our centaur herd. I think you, Horace, would have known better than to stride into the forest and call a horde of angry centaurs filthy half-breeds."
- — Albus Dumbledore and Horace Slughorn talking about the results of Umbridge's actions[src]
Umbridge was ultimately rescued by Dumbledore, although she was apparently left with a significant fear of centaurs afterwards, reacting violently at even the sound of hoof-beats. How Dumbledore managed to rescue her from the human-hating centaurs without suffering any injury himself remained a mystery, though it is likely that centaurs had respect for Albus, based on their salute at his funeral.
- Harry Potter and the Order of the Phoenix
- Harry Potter and the Order of the Phoenix (film)
- Harry Potter: The Creature Vault (mentioned only)
Differences between the book and film
- In the book, Bane solely carried Umbridge off into the forest, but in the film she was carried off by two Centaurs, neither of which seemed to be Bane.
- In the film, none of the Centaurs speak to Umbridge or the children.
- The Centaurs do not threaten or attack Harry and Hermione in the film, but just leave them.