First Battle of Hogwarts

The First Battle of Hogwarts was the final and only battle of the second phase of the War of Magic.

Prelude
After discovering the true circumstances of Harry's birth, Dumbledore realised that Thor was choosing to remain imprisoned and that his defeat in the first phase of the War of Magic must have been staged.

Seeking to end the conflict once and for all, Dumbledore summoned his old allies Gandalf and Dr. Strange. Using the power of the Time Stone, the wizards attempted to trap the Odinson in a time loop in Hogwarts, allowing them the time to discover how to kill him once and for all.

The plan seemed at first, but Thor used the power over the other five stones to break the loop and expel the wizards from the castle. Realizing that with the Time Stone in Strange's hands he could not escape, Thor used the reality stone to create a barrier around the castle and sealed the inhabitants of the castle in a pocket dimension.

He demanded the return of the Time Stone and his safe passage out of the dimension in exchange for their release. Understanding that if he completed the Infinity Gauntlet again he would become unstoppable, the wizards refused to negotiate and summoned their respective forces for an assault on the castle.