Fred and George Weasley's departure from Hogwarts

Fred and George Weasley's Departure from Hogwarts took place sometime after the Easter Holidays in 1995, after rebelling against Umbridge and the Inquisitorial Squad for most of the year.

Events Leading up to Their Departure

 * Joining Dumbledore's Army with a number of other students
 * Selling Weasleys' Wizard Wheezes products that they had perfected to Hogwarts students
 * Shoving Graham Montague into the Vanishing Cabinet after he tried to dock a large amount of House Points from them
 * Setting off their entire stock of Weasleys' Wildfire Whiz-bangs all through Hogwarts
 * Placed a Portable Swamp in the hallway near Professor Umbridge's office of Hogwarts

Departure
The twins placed their Portable Swamp in the hallway near Professor Umbridge's office so that Harry Potter could use Umbridge's fireplace to speak to Sirius Black via The Floo Network. When Harry was finished speaking to them, Filch came into Umbridge's office, happily saying that he had permission to whip wrongdoers. He did not see Harry, as Harry had his Invisibilty Cloak.

Fred and George Summoned their broomsticks from Umbridge's office, and flew out of Hogwarts, after advertising their shop.

Aftermath
"Give her hell from us, Peeves."

- Fred instructing Peeves the Poltergeist to cause trouble in Hogwarts

Along with Peeves, many other students attempted to become "Troublemakers-in-Chief". Lee Jordan had been setting Nifflers into Umbridge's office, students often dropped Dungbombs and Stink Pellets, and many students who had bought Skiving Snackboxes put use to them while in Umbridge's classes.