The creation of Hogwarts School of Witchcraft and Wizardry came sometime between 990 and 1000 A.D., by the greatest magicians of the time: Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin. Using the magical Sorting Hat, each founder created their own House within the school to train students with specific characteristics that the founders particularly valued. Over time, Hogwarts came to be known not just as the best wizarding school in the world, but also one of the most powerful magical institutions on the planet.
Slytherin believed that Hogwarts should only be open to "purebloods," i.e., students born from wizarding families. The other founders, led by Gryffindor, believed that the school should be to open to everyone, including "half-bloods" (those with only wizarding parent) or even witches and wizards from entirely Muggle families, known as "Muggle-borns" (or, to some, the extremely derogatory "mudbloods"). The issue became so heated that Slytherin gave up his position at the school in anger. Years after he left, rumors grew that Slytherin had created a secret chamber within Hogwarts as the resting place for a monster that would one day wake up and rid the school of non-purebloods. Slytherin's obsession with pureblood superiority echoed through the ages would find expression centuries after his death in the form of Lord Voldemort and the Death Eaters.
The story of the Peverell brothers: Antioch, Cadmus, and Ignotus. Legend says the three brothers were gifted certain objects by Death itself — a powerful wand, an invisibility cloak, and a stone to bring dead people back to life — which would allow them mastery over Death itself. Dumbledore theorized that the brothers in the story were gifted magicians who, possibly in the 13th century, managed to create three immensely powerful magical objects ( collectively called the "Deathly Hallows") that in combination would allow the user to become impervious to any harm.
Shortly after graduating from Hogwarts, Albus kindled a friendship (and romance) with the equally brilliant young wizard Gellert Grindelwald, recently expelled from his own school. Together, Dumbledore and Grindelwald sought to confirm the existence and location of the Deathly Hallows. The duo's dreams of ruling the world of Muggles and wizards alike as benevolent dictators were shattered, however, when Dumbledore discovered the extent of Grindelwald's cruelty. Grindelwald got into an argument with Albus' disapproving younger brother, Aberforth. They started dueling, and Dumbledore was forced to take up arms as well. During the chaos, Ariana was killed. Grindelwald panicked and fled, and Dumbledore was left to pick up the pieces, along with a lifelong guilt over his role in the death of his sister.
After his fallout with Dumbledore, Grindelwald continued on his dark path alone. He worked in secret for many years amassing an army. Most notably, in 1905, Grindelwald was able to locate and acquire the legendary Elder Wand after stealing it from its previous owner, famed wandmaker Mykew Gregorovitch. More powerful than ever, Grindelwald set about plotting his rise to power and plans for world domination. Dumbledore wished to avoid confronting his former friend and sent Newt Scamander and other allies to stop Grindelwald, instead. When those efforts proved in vain, Dumbledore had no choice but to take matters into his own hands. He finally entered into open war with Grindelwald in 1945, and two ultimately engaged in a wizarding duel that is widely considered the most legendary magical battle of all time. Although Grindelwald was a formidable adversary, Dumbledore managed to win by a hair's breadth. Grindelwald was defeated and imprisoned, and Dumbledore became the new master of the Elder Wand, and the most powerful wizard in the world.
In a small village in Britain, a witch named Merope Gaunt, a direct descendant of Salazar Slytherin, lured a handsome Muggle into marriage through magical trickery. The result of this unfortunate union was a boy whom Merope named Tom Marvolo Riddle. After his father abandoned Merope, who died in childbirth, Riddle was raised in a Muggle orphanage in London until his 11th birthday, when he was invited to become a student at Hogwarts by none other than Albus Dumbledore himself. Riddle began studying at Hogwarts in 1938. Over the next few years, the handsome and brilliant student discovered his connection to Salazar Slytherin and became convinced of pureblood superiority — despite the fact that Riddle himself was a half-blood. Riddle also collected a coterie of followers and became obsessed with the idea of conquering death. His obsession continued after he graduated from Hogwarts, and he spent the next few decades delving deeply into the forbidden arts. Riddle's experiences fundamentally changed him, both mentally and physically, and he emerged from his own experiments as the dreaded dark wizard, Lord Voldemort.
Having assumed the identity of Lord Voldemort, Tom Riddle set about expanding his network of followers to include giants, dementors, werewolves, and all manner of foul magical creatures. With a formidable army now at his command, Voldemort launched an all-out attack against the wizarding world in Britain, seeking to overthrow the Ministry of Magic and set himself up as a new despot. Rumors of Voldemort's power and cruelty grew to such proportions that people were afraid to say his name, instead calling Voldemort "He-Who-Must-Not-Be-Named" or "You-Know-Who." Despite his might, however, Voldemort appeared reluctant to directly confront his former teacher, Albus Dumbledore, who had his own army: the Order of the Phoenix. Two members of the Order were Lily and James Potter, who, in 1980, were expecting their first son. That same year, a prophecy was delivered by controversial seer Sybill Trelawney, predicting that a child "born as the seventh month dies" would be the cause of Voldemort's defeat. In 1981, acting on the words of the prophecy, Voldemort visited the home of the Potters. After killing Lily and James, the Dark Lord delivered the killing curse to their infant son, Harry. But by sacrificing herself for Harry, Lily had invoked a powerful protective magic, which caused the curse to deflect and rebound upon its caster. While not actually killed as the wizarding world believed, Voldemort's power broke, and he was forced to flee in a ruined and disembodied state.
As news of Voldemort's defeat began to spread, Dumbledore acted quickly, depositing the infant hero in the care of Lily's sister, Petunia, a Muggle who lived with her husband, Vernon Dursley, and their son, Dudley. The Dursleys intensely disliked magic of any kind, but (very begrudgingly) allowed Harry to stay with them, though his childhood with the Dursleys was defined by hardship and abuse. As Vernon and Petunia had concealed the truth of Harry's magical heritage, it fell to Hogwarts gamekeeper and Dumbledore's right-hand man Rubeus Hagrid to personally visit Harry on his 11th birthday and tell him there was a place waiting for him at the greatest magical school in the world. Confused and full of doubts, Harry arrived at Hogwarts to find he was viewed as a great hero for defeating Voldemort, an incident he did not remember. Harry uncovered a plot by Lord Voldemort, who had possessed a Hogwarts professor name Quirrell, to return to power using the fabled philosopher's (or sorcerer's) stone. Although Harry was able to keep the stone from Voldemort's clutches, Dumbledore warned him that the Dark Lord was not truly defeated and remained a threat to the wizarding world, particularly Harry.
Harry's second year at Hogwarts began with he and Ron crashing a flying car into an ancient magical tree on the Hogwarts grounds. The duo barely escaped expulsion, and the year went downhill from there. Most ominously, Harry was persistently targeted by a house-elf named Dobby, who repeatedly attempted to keep the young wizard away from Hogwarts. The nature of the danger Dobby warned of soon became apparent when students, ghosts, and animals began experiencing attacks by some unseen force. A message written in blood on the walls of the school declared that the secret chamber created by Salazar Slytherin to rid the school of witches and wizards of Muggle parentage had once again opened. As Harry and his friends tried to get to the bottom of the mystery, students continued to get attacked, Dumbledore was removed from his post as headmaster, and the school came close to getting shut down. After several hair-raising adventures, Harry and Ron discovered that the Chamber of Secrets had been opened by a remnant of Tom Riddle's soul, preserved in his school diary and acting through Ron's mind-controlled little sister, Ginny. Harry felt compelled to confront Riddle directly, as well as the giant snake known as the basilisk, which was responsible for attacking the students. Harry managed to defeat Riddle, and in the process discovered a mysterious connection between himself and the villain that would soon come back to haunt him.
Unfortunately, despite the fact that he wasn't old enough to participate, Harry was magically and mysteriously declared one of the four Triwizard champions. Ron broke off their friendship over feelings of jealousy at the attention Harry was receiving, and the young wizard had to rely on the help of Hagrid, Hermione, Dobby, and their new teacher, "Mad Eye" Moody, to get through the three tasks of the tournament while competing against the older contestants. The contest ended when Harry and fellow Hogwarts student Cedric Diggory touched the Triwizard Cup simultaneously ... only to be suddenly and unexpectedly transported to a graveyard. It turned out that Harry's entry in the tournament had been part of a plan concocted by Lord Voldemort and his lackeys. After killing Cedric, Voldemort used Harry's blood to enact a ritual that restored him to his old body, more powerful than ever. Somehow managing to escape certain death at the hands of the Dark Lord, Harry returned to Hogwarts to inform Dumbledore that the most powerful dark wizard of all time had returned once again to wreak havoc on the world.
With Dumbledore's help, Harry learned the true nature of Voldemort's seeming immortality, which lay in the six pieces of the Dark Lord's soul that Voldemort had detached from his body and stored inside special items called Horcruxes. In order to kill Voldemort for good, each part of his soul needed to be destroyed; Dumbledore and Harry had already destroyed one apiece, and Dumbledore intended them to hunt the other four together. Harry's faith in Dumbledore was shaken, however, when he discovered that it was Severus Snape who had overheard the prophecy regarding Harry and Voldemort during his time as a Death Eater, and relayed the information to the Dark Lord, leading to the death of Harry's parents. Yet Dumbledore continued to trust that Snape had reformed. This trust appeared to backfire at the end of the school year when, after a difficult quest to retrieve another of Voldemort's Horcruxes, a weakened Dumbledore was murdered by Snape in front of Harry's eyes.
After Dumbledore's death, Voldemort moved into the open, declaring all-out war against the old order. The Ministry of Magic had been infiltrated and was now run completely by Voldemort's lackeys, and there was a bounty on Harry, Ron, and Hermione's heads that forced them to go on the run. The trio devoted most of what would have been their final year at Hogwarts to finding and destroying the remaining Horcruxes. In the process, Harry discovered the legend of the Deathly Hallows and learned that, thanks to Dumbledore's planning, he possessed two of them. The third, the Elder Wand, was taken from Dumbledore's grave by Voldemort, who killed Snape to become its master. The trio's Horcrux hunt took them from the Ministry to Godric's Hollow to Gringotts, the wizard bank, and ultimately back to Hogwarts, which was now under the control of the Death Eaters. Voldemort himself converged on the school, but Harry's return rallied the resistance, and the Battle of Hogwarts began. Only when Voldemort demanded that Harry meet him face-to-face did Harry discover that a final part of Voldemort's soul resided in Harry's own body. Dumbledore's plan, years in the making and assisted by Snape, finally bore fruit when Voldemort inadvertently destroyed the part of his soul inside Harry with another killing curse. Harry also deduced that he was the true master of the Elder Wand, and with Voldemort out of Horcruxes, Harry used it to put a permanent end to the Dark Lord.
It was a long, difficult road to recovery for the wizarding world following Voldemort's defeat. Harry and his allies were regarded as legendary heroes, but they still had to deal with the trauma and the losses incurred due to the years of battling the Dark Lord's army. Many of Harry's closest friends were dead, and he had to learn to become a source of strength for those that remained and the wizarding world at large. Faced with difficult decisions, Harry choose to willingly give up his claim over the Elder Wand, which he put back in Dumbledore's tomb. He fulfilled his childhood dream of becoming an auror (a dark wizard catcher), and rose rapidly through the ranks to become the head of his department at a young age. Harry also occasionally delivered lectures at Hogwarts and married Ginny (who herself became a Quidditch star and later a journalist), starting a family that eventually grew to include three children. Harry remained close to Ron and Hermione, who got married and started a family of their own. Despite his fears, Harry's ancient connection to Voldemort did not bother him anymore, and he was able to lead some semblance of a normal life after making peace with his old allies as well as enemies, including Dudley Dursley and Draco Malfoy.