The Second Wizarding War: Years 5-7

This period, spanning Harry Potter's fifth year through the conclusion of the Second Wizarding War, marks the public return of Lord Voldemort and the ensuing conflict that engulfed the entire British wizarding world. It begins with the Ministry of Magic's campaign of denial against Harry Potter and Albus Dumbledore, leading to the establishment of the oppressive High Inquisitor at Hogwarts. The core of this era is defined by the efforts of the reconstituted Order of the Phoenix and Dumbledore's Army to resist the Death Eaters, the revelation of the prophecy concerning Harry and Voldemort, and the critical hunt for Voldemort's Horcruxes. The period culminates in the Battle of Hogwarts and the final defeat of Lord Voldemort.

The fifth year is characterized by the Ministry of Magic's refusal to accept Voldemort's return, leading to a direct conflict with Dumbledore and Harry.

• Dementor Attack: Two Dementors attack Harry Potter and Dudley Dursley in Little Whinging, forcing Harry to perform a Patronus Charm and face a disciplinary hearing at the Ministry of Magic.
• Order of the Phoenix: The Order re-forms, using Number Twelve, Grimmauld Place as its headquarters to secretly combat Voldemort's activities.
• Dolores Umbridge at Hogwarts: To control the school, the Ministry installs Dolores Umbridge as the Defence Against the Dark Arts professor and later as the first Hogwarts High Inquisitor. She bans practical defensive magic.
• Dumbledore's Army: In response to Umbridge's poor teaching, Harry, Ron Weasley, and Hermione Granger form a secret student group, Dumbledore's Army (the D.A.), to learn practical Defence Against the Dark Arts in the Room of Requirement.
• The Prophecy: Harry has disturbing dreams and visions connected to Voldemort, culminating in a vision of Arthur Weasley being attacked by Nagini, which proves to be true. He begins Occlumency lessons with Severus Snape to shield his mind.
• Azkaban Breakout: Ten high-security Death Eaters, including Bellatrix Lestrange, escape from Azkaban.
• Battle of the Department of Mysteries: Lured by a false vision of Sirius Black being tortured, Harry and several members of the D.A. travel to the Department of Mysteries. They are ambushed by Death Eaters seeking to retrieve the prophecy. Members of the Order of the Phoenix arrive, and in the ensuing battle, Sirius Black is killed.
• Voldemort's Return Confirmed: Voldemort himself appears at the Ministry, dueling Dumbledore in the Atrium before disapparating. His return is witnessed by Cornelius Fudge and other Ministry officials, forcing them to finally admit the truth.

With the Second Wizarding War now public, the atmosphere grows darker. The central focus shifts to uncovering the secret to Voldemort's immortality.

• New Teachers: Horace Slughorn returns from retirement to teach Potions, while Severus Snape finally achieves his ambition of becoming the Defence Against the Dark Arts professor.
• The Half-Blood Prince: Harry excels in Potions by using a second-hand textbook filled with helpful annotations, signed by its mysterious former owner, the “Half-Blood Prince”.
• Voldemort's Past: Dumbledore gives Harry private lessons using the Pensieve, showing him memories of Tom Riddle's past to understand his enemy's motivations and weaknesses.
• Horcruxes: Through the memories, Dumbledore reveals his theory that Voldemort created multiple Horcruxes to achieve immortality. The final crucial memory, obtained from Slughorn, confirms that Voldemort intended to create six Horcruxes.
• Draco Malfoy's Mission: Harry becomes suspicious of Draco Malfoy, correctly guessing that he has been tasked with a mission by Voldemort. Malfoy attempts to smuggle Death Eaters into Hogwarts using a pair of vanishing cabinets.
• The Cave: Dumbledore and Harry travel to a seaside cave to retrieve a Horcrux, Slytherin's Locket. They succeed, but the ordeal severely weakens Dumbledore.
• Battle of the Astronomy Tower: Upon their return to Hogsmeade, they discover the Dark Mark over Hogwarts. Death Eaters, let in by Malfoy, have invaded the castle. On the Astronomy Tower, a weakened Dumbledore is disarmed by Malfoy before being killed by Severus Snape with the Killing Curse.
• The Quest: After Dumbledore's funeral, Harry discovers the locket they retrieved is a fake. He vows not to return to Hogwarts for his seventh year and instead dedicate himself to finding and destroying the remaining Horcruxes, with Ron Weasley and Hermione Granger pledging to join him.

The final year of the conflict sees the trio abandon their formal education to undertake a perilous quest across the country, while Voldemort seizes total control of the wizarding world.

• Battle of the Seven Potters: The Order of the Phoenix's plan to move Harry from Privet Drive is ambushed, resulting in the deaths of Alastor Moody and Hedwig.
• The Fall of the Ministry of Magic: Voldemort and his Death Eaters assassinate Minister for Magic Rufus Scrimgeour and take over the Ministry, installing Pius Thicknesse as a puppet Minister and creating a Muggle-Born Registration Commission led by Dolores Umbridge.
• The Horcrux Hunt: Harry, Ron, and Hermione spend months on the run, searching for the remaining Horcruxes. They successfully retrieve Slytherin's Locket from Umbridge at the Ministry.
• The Deathly Hallows: The trio learns about the Deathly Hallows—the Elder Wand, the Resurrection Stone, and the Invisibility Cloak—a parallel quest that distracts them but proves essential to the final victory.
• Destruction of Horcruxes: Over the course of the year, several Horcruxes are destroyed: Slytherin's Locket by Ron Weasley with the Sword of Gryffindor, Hufflepuff's Cup by Hermione Granger with a Basilisk fang, and Ravenclaw's Diadem by Vincent Crabbe's Fiendfyre.
• Battle of Hogwarts: The search for the final Horcruxes leads the trio back to Hogwarts, sparking a massive final battle between Voldemort's army and the combined forces of Hogwarts students, staff, the Order of the Phoenix, and their allies.
• Final Confrontations: During the battle, Snape is murdered by Voldemort. Harry learns from Snape's memories that he himself is an unintentional seventh Horcrux. He willingly goes to his death, allowing Voldemort to destroy the piece of soul within him. Harry survives due to the protection from his mother's sacrifice.
• Voldemort's Defeat: In the final duel, Voldemort's Killing Curse rebounds off Harry's Disarming Charm because Harry is the true master of the Elder Wand. Lord Voldemort is killed, ending the Second Wizarding War.

• Resistance and Rebellion: The formation and actions of Dumbledore's Army and the Order of the Phoenix showcased organized resistance against tyranny, even in the face of overwhelming odds and government opposition.
• Moral Complexity: The later books delved into the moral gray areas of supposedly “good” characters like Albus Dumbledore, and the complex motivations of characters like Severus Snape and Draco Malfoy.
• The Nature of Power: The narrative explores different forms of power, contrasting Voldemort's pursuit of dominance and immortality with the power of love, loyalty, and self-sacrifice embodied by Harry and his allies.
• Loss and Sacrifice: This period is defined by immense loss, with numerous beloved characters sacrificing their lives. This theme culminates in Harry's own willing sacrifice, which is central to Voldemort's defeat.

1. Sirius Black (Killed during the Battle of the Department of Mysteries)
2. Albus Dumbledore (Killed during the Battle of the Astronomy Tower)
3. Alastor "Mad-Eye" Moody (Killed during the Battle of the Seven Potters)
4. Hedwig (Killed during the Battle of the Seven Potters)
5. Rufus Scrimgeour (Killed during the fall of the Ministry of Magic)
6. Dobby (Killed by Bellatrix Lestrange at Malfoy Manor)
7. Fred Weasley (Killed during the Battle of Hogwarts)
8. Remus Lupin (Killed during the Battle of Hogwarts)
9. Nymphadora Tonks (Killed during the Battle of Hogwarts)
10. Colin Creevey (Killed during the Battle of Hogwarts)
11. Severus Snape (Killed by Nagini on Voldemort's orders)
12. Bellatrix Lestrange (Killed by Molly Weasley during the Battle of Hogwarts)
13. Lord Voldemort (Killed by his own rebounding curse in the final duel)