Tales of dating and danger
A.) was a secret organisation initiated by Harry Potter, Hermione Granger, and Ron Weasley to teach their fellow Hogwarts colleagues proper Defence Against the Dark Arts in 1995.
It was founded by Hermione, but taught and led by Harry.
Lessons continued during the early months of 1996, and the mass breakout of imprisoned Death Eaters from Azkaban spurred them on to greater efforts, particularly Neville Longbottom, whose friends learned that three of the escapees had tortured Neville's parents into insanity at the end of the First Wizarding War.
They claimed that Cedric Diggory's death was a "tragic accident", and refused to admit that Voldemort had murdered him.
Concerned that they needed defensive magical skills to combat Lord Voldemort and his Death Eaters, Hermione proposed the formation of a practical study group to be taught by Harry as he had more experience than any of them with using actual defensive and offensive magic following his encounters with Lord Voldemort.
After some initial scepticism, the students started to list Harry's achievements — the survival of his parents' murder at Voldemort's hands in their family home and resulting defeat of the dark wizard himself as an infant (which earned Harry his fame from the wizarding community and the title "the Boy Who Lived"), rescue of the Philosopher's Stone from a disembodied Voldemort in his first year, slaying of the Basilisk of Slytherin in the Chamber of Secrets with the Sword of Gryffindor in his second year, vanquishing of the Dementors of Azkaban at the Black Lake with a corporeal stag Patronus Charm in his third year, and winning of the Triwizard Tournament and duel with the resurrected Voldemort within the Little Hangleton graveyard in his fourth year.
The group agreed that secrecy would be vital — if Umbridge found out about them, they would surely be shut down and punished.