So Umbridge acquires the locket as a bribe from Mundungus Fletcher, and though it once belonged to Salazar Slytherin, Merope Gaunt, and Hepzibah Smith, Umbridge is unaware that the locket is one of Lord Vodemort's Horcruxes - or that it belonged to him at all.
At some point, Umbridge received a locket as a bribe from thief Mundungus Fletcher. The pendant was actually Salazar Slytherin's locket and was, unbeknownst to her, one of Voldemort's Horcruxes.
If anything the Locket may have been channeling her anti-muggle hatred and expanding on it. Dolores Umbridge complemented Voldemort's essence well so there really was no negative effect just an expansion on how Umbridge already acted.
Did Voldemort know Dolores had the locket? Yes, but Voldemort is convinced that no one knows he made Horcruxes. And that the Horcrux is safe in the cave. Besides, he would never allow anyone to wear the Slytherin locket.
She definitely knew. Everyone knew, but she didn't care. She was a Voldemort sympathizer, because he preached everything she believed in.
Yup, that's right: when the Death Eaters killed Mad-Eye, and then took over the Ministry, they apparently gave Mad-Eye's "mad eye" to Umbridge. Who then installed it in her door to use as a way of spying on her fellow wizards.
Dolores Umbridge is in a position of power and is allowed to stay in it even after abusing it. Lord Voldemort, on the other hand, is evil, whereas Umbridge believes she is one of the good ones and that her actions are justifiable, even necessary.
Harry Potter and the Deathly Hallows
In this book, Rowling reveals that Bellatrix is the guardian of Helga Hufflepuff's cup (though she is unaware that it is a Horcrux), which Voldemort has entrusted the Lestranges to keep in their Gringotts vault.
28, 1997: Ron Weasley destroys Salazar Slytherin's locket deep in the Forest of Dean, Gloucestershire, by stabbing it with Godric Gryffindor's sword.
Regulus Black is the brother of Sirius Black. He is also a former Death Eater, although he defied Voldemort and found, and intended to destroy, Salazar Slytherin's locket (a horcrux) and died when dragged into the lake and drowned by Voldemort's inferi.
Why does the horcrux locket affect Ron more than Harry and Hermione? Hermione and Harry have learned resilience to hunger and deprivation. Ron had not. It was harder for him to deal with it, simply because he did not know how.
Fans may have guessed this already, but Rowling confirms Umbridge is the only person other than Lord Voldemort to permanently scar Harry, when she forces him to write "I must not tell lies" in his own blood. She's a half-blood!
Result. Dolores Umbridge carried away by the centaurs, but is later rescued by Albus Dumbledore.
Two days later, Hepzibah was dead and her house-elf Hokey seemed to remember poisoning her mistress's cocoa. The cup and locket had both vanished. The cup, which was made a Horcrux with Hepzibah's death, was left with Bellatrix Lestrange who kept it at Gringotts.
There were many attendees of the funeral. A delegation of Ministry officials, including: Cornelius Fudge, Rufus Scrimgeour, Dolores Umbridge, and Percy Weasley.
Riddle tracked it down to the new owner, Hepzibah Smith, and killed her for it (HBP20). That was the "real" locket that was made into a Horcrux. Regulus Black became a Death Eater during the first war with Lord Voldemort, and it made his pureblood family proud, according to his brother Sirius.
The Dark Lord — aka Voldemort — created seven Horcruxes in an attempt to sustain immortality.
When Jo Rowling was asked on the Bloomsbury webcast who died to make Voldemort's seven Horcruxes, she answered: The diary ” Moaning Myrtle.
Gryffindor and Slytherin have the biggest rivalry at Hogwarts - but the two houses might be more similar than they would admit!
In addition, Lucius Malfoy and Arthur Weasley have a well-established feud despite being second cousins once removed by marriage.
Yep, that happened: Bellatrix and Voldemort had sex sometime around Order of the Phoenix or Half-Blood Prince, and their wild night in bed led to a child named Delphi Diggory/Riddle/Lestrange. According to Delphi herself, she was born sometime before the Battle of Hogwarts.
Suspecting a destiny-fuelled connection between two prophecy-touched individuals is one thing. Surmising that an infant houses a piece of an evil wizard's very soul within his body is an entirely different matter. At this point, Dumbledore doesn't even know about the Horcruxes at all.
Dolores Jane Umbridge (b. 26 August, 1961 or earlier) was a half-blood witch and a British Ministry of Magic bureaucrat who served as Senior Undersecretary to the Minister for Magic under Ministers Cornelius Fudge, Rufus Scrimgeour, and Pius Thicknesse.
Umbridge was already doing everything he wanted anyway (including torturing Harry)—she was already a Death Eater in all but name.