Notably, the vault was robbed in 1998 by Harry Potter, Hermione Granger, and Ron Weasley with the assistance of former Gringotts employee Griphook during the Second Wizarding War.
Griphook and an Imperiused Bogrod helped Harry, Ron and Hermione break into Bellatrix's vault and recover the Horcrux. The cup was destroyed by Hermione Granger, using a fang from the Basilisk's corpse.
It was carried out by Harry Potter, Ron Weasley, and Hermione Granger in order to steal one of Lord Voldemort's Horcruxes from the vault belonging to the Lestrange family.
In Harry Potter and the Deathly Hallows, the Trio, with the help of Griphook, execute a plan to break in to the Gringotts vault of Bellatrix Lestrange's family to steal a Horcrux belonging to Voldemort.
Not long afterwards, Hermione used some of Bellatrix's hair, which had fallen onto her clothes while Bellatrix held her hostage, to create Polyjuice Potion to impersonate Bellatrix. This made it possible for her, Harry and Ron to steal the Horcrux from the Lestranges' vault.
How did Harry know Hufflepuff Cup was in Bellatrix vault?
The clue he received in the film was from Bellatrix, who was in a frantic frenzy when she thought her vault was broken into. He is ultimately able to identify the cup as a Horcrux because of his ability to hear the piece of Voldemort's soul contained within them, an ability which is not present in the books.
Though Voldemort apparently punishes Bellatrix and the Malfoys severely for interrupting his Elder Wand side quest only to have Potter escape and steal the cup, she nevertheless fights for her master in the Battle of Hogwarts towards the end of the novel.
Did Bellatrix know she had a Horcrux in her vault?
At some point in time, Lord Voldemort gave Bellatrix Lestrange Hufflepuff's Cup, one of his Horcruxes, to keep safe in her vault, though he didn't tell her its true nature.
Which unforgivable curse did Harry use on Bellatrix?
For example, despite being furious with Bellatrix Lestrange for her murder of his godfather in 1996, Harry Potter was only able to cause her a brief moment of pain with the Cruciatus Curse because he used it out of "righteous anger", though he was still able to knock her off of her feet with it.
Honestly, Hermione knew Dobby was a lost case... nothing could have revived Dobby after the attack or she would have definitely helped Harry with Dobby considering she was the girl who started S.P.E.W(Society for the Elfish welfare) and fought for elf rights. There was nothing to be done at that point.
They know she's an impostor. They've been warned", so obviously the request for the wand was unexpected even to him. It's thus pretty safe to conclude that the real Bellatrix had reported her wand stolen and alerted Gringotts prior to the trio's attempted break in.
Why didn't they just show the goblin Bellatrix's wand?
They were asking because if she had Bellatrix's wand (which was stolen by Harry Potter) then she would be an accomplice of Harry. In the book, she gives them the wand and it alerts them that she is an imposter since the wand was known to be stolen. Harry then uses an imperius curse on the goblin in order to get in.
She was raised by Euphemia Rowle then Rodolphus Lestrange. It would not be very surprising if they told her everything about Voldemort, his greatness, his power, his ambitions… since he was their master.
Before her death, Bellatrix secretly gave birth to an illegitimate daughter named Delphini, whom she conceived with her beloved master, Lord Voldemort. Delphini was conceived sometime after the Battle of the Department of Mysteries in 1996 and before the Skirmish at Malfoy Manor in 1998.
He felt nothing for his family, and only wanted his friends in school to rally around him because he wanted to hold power over them. Bellatrix Lestrange was obviously in love with him and worshiped him, but he only cared for her servitude, not her. We know that he did not date anyone, even when at Hogwarts.
The result of the duel actually comes about as a result of nothing more than spectacular accuracy on Weasley's part. She casts a powerful, unnamed curse at Lestrange and manages to hit her directly in the heart, killing her instantly.
Due to his humiliation in the Triwizard Tournament, Cedric eventually becomes a Death Eater and kills Neville Longbottom. Due to Neville's death, the final Horcrux Nagini was never destroyed, and as a result Voldemort is never defeated, kills Harry and takes over the Wizarding World.
Still, any Horcrux would be far more vulnerable than the Sword of Gryffindor. If the sword were to be imbued with a soul fragment and therefore turned into a Horcrux, it would no longer be indestructible but vulnerable to Fiendfyre and basilisk venom—two substances it would have otherwise absorbed in its natural state.
However, despite being rescued by them, Griphook's general mistrust of wizardkind resulted in him betraying Harry Potter, Ron Weasley, and Hermione Granger. He betrayed them because he believed they would not hand him the Sword of Gryffindor, after destroying the Cup and other Horcruxes.
When the Boy Who Lived needed Griphook's help to break into Gringotts Wizarding Bank, the goblin demanded the sword of Gryffindor as payment. It was then that Harry learned that, according to Griphook, the sword rightfully belonged to his people, and his culture saw Gryffindor as a thief.
