When did Dumbledore know about Horcruxes?

Background information. During the 1996–1997 school year, Dumbledore began to share his findings regarding Voldemort’s Horcruxes with Harry Potter. Using the Pensieve, he showed Harry a series of memories about the boy who was Tom Riddle and the man who was Voldemort.

Did Dumbledore know Harry was a Horcrux in Chamber of Secrets?

It’s easy to forget, given his undeniable talent for knowing things and his astonishing powers of deduction. But Dumbledore does learn and discover and realize things throughout the Harry Potter series. And at this point, he still does not know about the Horcruxes.

Did Dumbledore know what a Horcrux was?

As a recap: at the time he died, Dumbledore knew for sure the identities of three out of seven Horcruxes — the destroyed diary and ring as well as an unsuspecting Harry Potter — and confidently hypothesized the identity of two more — Slytherin’s locket and Hufflepuff’s cup.

How/when did Dumbledore know about the 7 Horcruxes?

At which point did Dumbledore know/guess about the 7 Horcruxes? We know that Dumbledore knew about Horcruxes at least as early as Harry’s parents’ deaths (he stated to Snape that Voldemort would be back). And in Harry’s 6th year, he knew that there were 7 for sure, from real Slughorn memory.

How did Dumbledore acquire Slughorn’s (tampered) memory?

How did Dumbledore acquire Slughorn’s (tampered) memory? In Harry Potter and the Half-Blood Prince, Chapter 17, Dumbledore and Harry are using the Pensieve to experience the vital Slughorn memory (which was tampered with), and Harry is instructed to collect the untampered memory.

How do they know Voldemort uses Horcruxes in Harry Potter?

In Harry Potter and the Half-Blood Prince, Dumbledore orders Harry to retrieve the memory about the talk with Tom Riddle/Voldemort from Slughorn. The memory is said to be needed because it contains valuable information that is needed to defeat him. The result is that they know that Voldemort uses Horcruxes. Why do they not know this before?

How many horcruxes are there in Harry Potter?

Dumbledore already has a pretty good idea of what might be a Horcrux – Slytherin’s locket, the Peverell ring, and Hufflepuff’s Cup. With the diary, that’s already four. But Dumbledore has one huge unanswered question here: how many Horcruxes are there total?