Harry Potter and Albus Dumbledore's private lessons

These lessons took place over the course of Harry Potter's sixth year. Using the Pensieve, Professor Dumbledore taught Harry about Voldemort's past.

First Lesson
The first lesson took place at 8pm on a Saturday in early September 1996. The password to Dumbledore's office was Acid Pops.

Bob Ogden's memory
Harry witnesses an encounter between Bob Ogden, an employee of the Department of Magical Law Enforcement, and the pureblood Gaunt family. Significant revelations include:




 * Introduction of Marvolo Gaunt, Voldemort's grandfather and namesake.
 * Introduction of Morfin Gaunt, Voldemort's uncle, who he would encounter later.
 * Introduction of Merope Gaunt, Voldemort's mother.
 * Introduction of Tom Riddle Sr., Voldemort's muggle father and namesake.
 * Salazar Slytherin's locket, and the familial link of the Gaunts to Slytherin.
 * Marvolo Gaunt's Ring, and the familial link of the Gaunts to the Peverells (also the Resurrection Stone, although this would not be realized until much later).

Other discussions

 * Merope's use of a Love Potion to seduce Tom Riddle Sr., and his eventual abandonment of his wife and unborn child.

Second Lesson
The second lesson took place at 8pm on a Monday in mid October 1996.



Dumbledore's memory (#1)
Harry witnesses Albus Dumbledore's first meeting with the eleven-year old Tom Marvolo Riddle. Significant revelations include:
 * Voldemort's childhood growing up in an orphanage.
 * Voldemort's uncommonly powerful control of magic, even at a young age.
 * Voldemort's preference for acting alone, and lack of desire for friendship.
 * Voldemort's tendency to collect trophies.
 * Voldemort's dislike of anything "common", including the name Tom.
 * First mention of the seaside cave.

Other discussions

 * Merope's refusal to any longer use magic, the sale of the locket to Borgin and Burkes, and her death shortly after giving birth.

Third Lesson
The third lesson took place at 8pm one evening in early January 1997.

Morfin Gaunt's memory
Harry witnesses the sixteen-year old Tom Riddle encounter Morfin Gaunt as he seeks out his heritage. Significant revelations include:
 * Voldemort learns the truth about his mother and father, and his own status as a half-blood.
 * Voldemort's murder of his own father, as well as his grandparents, as retribution for his abandonment as well as the extermination of his muggle lineage, and the subsequent framing of the crime on Morfin.
 * Voldemort's theft of Marvolo Gaunt's Ring.



Slughorn's memory (fake)
Harry witnesses Tom Riddle question Horace Slughorn about Horcruxes. Key parts of the memory are omitted, as the memory had obviously been tampered with.
 * Dumbledore assigns Harry the task of obtaining the real memory from Slughorn.

Other discussions

 * Tom Riddle's years at Hogwarts, under the watchful eye of Albus Dumbledore.
 * Tom Riddle's school "friends", the forerunners of the Death Eaters.
 * Underage magic in wizarding homes.

Fourth Lesson
The fourth lesson took place at 8pm on a Monday in mid March 1997. The password to Dumbledore's office was Toffee Eclairs.



Hokey the House-Elf's memory
Harry witnesses the young Tom Riddle, now an emplyee of Borgin and Burkes, as he pays a visit to the elderly witch Hepzibah Smith. Significant revelations include:
 * Salazar Slytherin's Locket, a relic of the Hogwarts founders and Voldemort's birthright.
 * Helga Hufflepuff's Cup, another relic of the Hogwarts founders.
 * Voldemort's first known murder committed solely for personal gain, as he once more collects "trophies".

Dumbledore's memory (#2)
Harry witnesses the man who now openly calls himself Voldemort as he returns to Hogwarts with the intention of taking up a teaching position. Significant revelations include:
 * Voldemort's intention to gain influence over young wizards and witches, as he continues to build his power.
 * Voldemort's fondness for Hogwarts, and his desire to continue studying its secrets.
 * Voldemort's interest in obtaining more artifacts of the Hogwarts founders.
 * Voldemort's dispute with Dumbledore over the power of love in magic.
 * Voldemort's curse placed upon the D.A.D.A. position after Dumbledore turns him away.
 * Although not realized until later, Voldemort's placement of Rowena Ravenclaw's Diadem, now a Horcrux, in the Room of Requirement.

Other discussions

 * Dumbledore tries to impart to Harry the vital importance of Slughorn's memory to everything they are discussing.

Final lesson
The final lesson took place shortly after midnight on April 22nd, 1997. The password to Dumbledore's office was still Toffee Eclairs.



Slughorn's memory (real)
Harry witnesses Tom Riddle question Horace Slughorn about Horcruxes. Significant revelations include:
 * The nature of Horcruxes.
 * Voldemort's intention of creating a seven-part soul to attain immortality, through the use of six Horcruxes.

Other discussions

 * The status of Tom Riddle's Diary as a Horcrux, and its destruction.
 * The status of Marvolo Gaunt's Ring as a Horcrux, and its destruction.
 * The status of the locket and the cup as Horcruxes.
 * The likelihood of Nagini as a Horcrux.
 * The likelihood of an object of Ravenclaw's as a Horcrux.
 * The possibility, although unlikelihood, of an object of Gryffindor's as a Horcrux.
 * The importance of love in Harry's fight against Voldemort, and the difference that choices make in the destiny foretold by the prophecy.

Behind the scenes
In the film version of Harry Potter and the Half-Blood Prince, only Dumbledore's first memory (at the orphanage) and both the fake and real versions of Horace Slughorn's memory are shown. All the rest are omitted.

Appearances

 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows