Harry Potter's parents were killed fighting Voldemort, the evil wizard, when he was just one year old. Their deaths led Potter to join the fight against Voldemort later in his life.
Harry Potter, Ron Weasley, and Hermione Granger defeated the spirit of Voldemort who was possessing one of their professors. This action helped the wizard revolution by preventing the evil wizard from returning to life.
In the Chamber of Secrets, Potter and Weasley saved the life of Ginny Weasley and again helped the wizard revolution by preventing Voldemort's spirit from resurrecting.
Voldemort resurrected after killing one of Potter's classmates during the Triwizard Tournament. Potter fought him and outsmarted him, escaping to safety.
This was a setback for the revolution, but inspired Potter to continue fighting.
Potter battled Voldemort at the Ministry of Magic and helped to prevent him from taking the prophecy that could allow Voldemort to defeat the revolution.
No prophecy for you!
In the Battle of Hogwarts, Potter defeated Voldemort once and for all. The Wizarding War was won!