Dolores Umbridge

Personality

"She actively enjoys subjugating and humiliating others, and except in their declared allegiances, there is little to choose between her and Bellatrix Lestrange" (Pm).

Even from a young age Umbridge was "judgemental, prejudiced and sadistic" (Pm). She had a vehement opposition to part human species including half-giants, werewolves, centaurs and merpeople, stemming from a "terror of the unknown and the wild" (Pm): she persecuted Hagrid for his race, passed legislation against werewolves and campaigned for the captivity of merpeople (OP14). Her extreme anti-Muggle and anti-part-human opinions tended to shock even the most pro-pureblood wizards (Pm).

Early life
Sorted into Slytherin, Dolores did not enjoy her time at Hogwarts due to what she felt was unrecognition of her talents from the staff (Pm) and, presumably, was not hugely popular with her peers. She joined the Ministry of Magic straight out of school as an intern in the Improper Use of Magic Office; promoted to Head of the Office before she was thirty, she subsequently continued to rise steadily through the Department of Magical Law Enforcement. Helping her up this career ladder was her drive and ambition, her ruthless lack of conscience (which was not averse to taking credit for others' work when the opportunity arose), and her obsequious charming of her superiors. She always vehemently denied any connection to her father, who had worked for Magical Maintenance, and people who asked about him tended to regret it. By giving him a small allowance she had persuaded her father to retire and remain out of the public eye, and pretended to all at the Ministry that her father was dead and had been an acclaimed Wizengamot member. People generally learned to stay on Umbridge's good side and pretended to believe this story. Though having no interest in marriage as a personal endeavour, she was determined to find a husband in the Ministry to further boost her status (though these attempts were unsuccessful) (Pm).

Harry Potter and Hogwarts
Umbridge was a force to be reckoned with for Harry Potter even before he caught his first glimpse of her. She was a strong proponent of the Ministry’s efforts to discredit Dumbledore and silence Harry, so she eventually took the law into her own hands and sent two Dementors to Little Whinging to attack Harry (OP32), presumably knowing that he would either be Kissed, or would use magic and so give an excuse to expel him. When he used a Patronus to defend himself and his cousin, he was brought in for a disciplinary hearing for performing underage magic. Umbridge was at the hearing and argued for Harry to be convicted, but Dumbledore swung the opinions of most of the Wizengamot toward him and he was cleared (OP8).

Partly in response to this failure of her plans, she conspired with Fudge to find a way to control both the boy and the Headmaster: taking advantage of his increasing paranoia, she convinced Fudge that she was "one of the few he could trust" (Pm), and so managed to install herself at the centre of the Ministry. The Minister assigned her to the job of Defence Against the Dark Arts teacher when Dumbledore was unable to find someone to fill the post (OP11).

Once at Hogwarts, Umbridge used Fudge's support to force a "reform" of the school. In classic government doublespeak, she told the Hogwarts staff and students: "Let us move forward, then, into a new era of openness, effectiveness and accountability, intent on preserving what ought to be preserved, perfecting what needs to be perfected, and pruning wherever we find practices that ought to be prohibited" (OP11).

"Wands away and quills out, please"
Umbridge's true role was to be spy for the Minister Fudge and an agent in his attempt to discredit Harry and Dumbledore, establishing authoritarian control over every aspect of Hogwarts. It certainly wasn't to teach Defence Against the Dark Arts skills; her "carefully structured, theory-centered, Ministry-approved course of defensive magic" taught no practical skills at all. Students learned theories about duelling and defence but were not allowed to actually practice the spells, even though practical tests were part of their exams (OP12). Fudge feared that Dumbledore would raise an army from the students if they were taught "combat" skills (OP14).

She singled Harry out for abuse immediately, goading him into arguments and then "triumphantly" punishing him for "spreading evil, nasty, attention-seeking stories" about Voldemort (OP13). In some of the creepiest scenes in the books, Harry is forced to write "I must not tell lies" with a magical quill that literally cut whatever he wrote on paper into the skin of his hand. Over and over and over again. The scars from this are still there over two years later (DH18), and possibly for the rest of Harry's life.

Ironically, Umbridge's tyranny and repression were the catalysts for the formation of Dumbledore's Army, an idea of Hermione's that had a tremendously positive impact on the rest of Harry's fifth year. Finally, we see Harry shine as a leader of his fellow students, a group as disparate as the Weasley twins and Neville Longbottom.

High Inquisitor
Umbridge also tried to control the staff, and when her efforts to interfere were rebuffed, she appealed to Fudge who made her the High Inquisitor of Hogwarts. This gave her the power "to inspect her fellow educators and make sure that they are coming up to scratch" (quoting Percy Weasley, now a Ministry shill) (OP15). In this position she bullied other staff, overruling them and browbeating them, and eventually sacking Trelawney and Hagrid. Together, Umbridge and Fudge used Nazi-like edicts to eat away at Dumbledore's control of Hogwarts.

Umbridge vs. Hogwarts faculty:

• Flitwick: treated her like a guest; not disciplined (OP15).
• Trelawney: put on probation (OP17) and her classes were "inspected" repeatedly. When Umbridge attempted to dismiss her, Dumbledore blocked her removal from the castle and appointed Firenze to teach Divination (OP26).
• McGonagall: openly hostile (OP15). When McGonagall tried to stop Hagrid's eviction, Umbridge's henchmen shot her with four Stunners (OP32).
• Grubbly-Plank: approved (OP15).
• Snape: relatively passive under her pointed questions about his interest in the DADA position (OP19). Put on probation anyway when he refused to make a second batch of Veritaserum (OP32).
• Hagrid: Could not account for why he arrived two months late for school term (OP20) - Hagrid didn't know what hit him (OP21). His classes were "inspected" repeatedly before and after he was put on probation. Eventually Umbridge (together with five other Ministry officials including Dawlish the Auror) tried to evict Hagrid one night but he escaped with Fang beyond the boundaries of Hogwarts (OP32).

Hogwarts High Inquisitor Educational Decrees:

• 22: "In the event of the current Headmaster being unable to provide a candidate for a teaching post, the Ministry should select an appropriate person." (30th August) (OP15)
• 23: "which creates the new position of Hogwarts High Inquisitor." (OP15)
• 24: "No student organization, society, team, group or club may exist without the knowledge and approval of the High Inquisitor." (OP17)
• 25: "The High Inquisitor will henceforth have supreme authority over all punishments, sanctions and removal of privileges pertaining to the students of Hogwarts, and the power to alter such punishments, sanctions and removals of privileges as may have been ordered by other staff members." (OP19)
• 26: "Teachers are hereby banned from giving students any information that is not strictly related to the subjects they are paid to teach." (OP25)
• 27: "Any student found in possession of the magazine The Quibbler will be expelled." (OP26)
• 28: "Dolores Jane Umbridge (High Inquisitor) has replaced Albus Dumbledore as Head of Hogwarts School of Witchcraft and Wizardry." (OP28)
• 29 (planned, may not have been passed): "You filthy little beasts would never have dropped Stink Pellets if you'd known I [Filch] had it in my power to whip you raw, would you now? Nobody would have thought of throwing Fanged Frisbees down the corridors if I could've strung you up by the ankles in my office, would they? But when Educational Decree Number Twenty Nine comes in, Potter, I'll be allowed to do them things..." (OP28)

Inquisitorial Squad
The Inquisitorial Squad was a group of students that Umbridge hand-picked to be her spies and enforcers (OP28). Members were apparently all from Slytherin and included Draco, Crabbe, Goyle, Montague (OP28), Warrington,  Pansy Parkinson (OP30), Millicent Bulstrode, and an unidentified sixth year Slytherin girl (OP32).

Mayhem
When the D.A. was caught, Dumbledore took the blame and left the school, and Umbridge became the Headmistress. By this time, however, the students and staff had begun to fight back and Umbridge found herself facing a low level mutiny, led joyfully by the Weasley twins and Peeves (OP28, OP29).  The more she cracked down, the more the rebellion took hold and flourished. In the end, Umbridge’s battle with the students took her into the Forest where she was carried off by centaurs (OP33). She left Hogwarts castle in disgrace some days later, chased by Peeves along with hoards of cheering students (OP38).

Allegiances ("What Cornelius doesn't know won't hurt him")
Umbridge appears to be doing Cornelius Fudge's bidding and seems to worship him sycophantically, keeping a framed photograph of him on her desk; however, she later boasts about sending Dementors to Little Whinging without Fudge's knowledge and almost illegally uses the Cruciatus Curse on Harry ("what Cornelius doesn't know won't hurt him") (OP32). According to Draco, Umbridge is very close to Lucius Malfoy (OP17). When she was made Headmistress she went to great lengths to gain Argus Filch's allegiance and loyalty (OP28).

Muggle-born repression and finally, justice
Umbridge returned to the Ministry from her stint at Hogwarts "shaken but unrepentant"; the chaos of Voldemort's return meant that she faced no retribution for her actions during the previous year as new Minister Rufus Scrimgeour had many more pressing concerns (Pm). When the Death Eaters took over the Ministry, Umbridge found herself among like-minded people. She developed the policy of sending Muggle-born wizards to Azkaban and chaired the Muggle-born Registration Commission (DH13). Umbridge may have had worries that her own ancestral background would not stand up to scrutiny, as she purchased the stolen Slytherin locket from Mundungus and passed it off as a Selwyn family heirloom (DH10, DH13). It's heavily implied that she personally authored the Ministry advice pamphlet on "Mudbloods and the Dangers They Pose to a Peaceful Pure-Blood Society", and she must have had connections to Death Eaters to acquire the magical eye of Mad-Eye Moody, which she stuck in her office door and used to spy on her employees (DH13). After the war, she was arrested and charged with crimes against Muggle-borns. She was convicted by the Wizengamot of imprisonment, torture and the deaths of several people, and sent to Azkaban (BLC, Pm).