Great War

"There's only one war that matters: the Great War, and it is here."

- Jon Snow

The Great War was a conflict that took place following the conclusion of the War of the Five Kings between the Night King, his legions of White Walkers and their undead thralls, and the living peoples of Westeros under the leadership of Jon Snow, the King in the North.

Prelude
"Jeor Mormont and Jon Snow both understood that the real war isn't between a few squabbling houses. It's between the living and the dead. And make no mistake my lady, the dead are coming."

- Davos Seaworth

See main articles: The Long Night, and Conflict Beyond the Wall

Season 7
"If we don't put aside our enmities and band together we will die. And then it doesn't matter whose skeleton sits on the Iron Throne."

- Davos Seaworth

In the books
In the A Song of Ice and Fire novels, the Great War, while heavily referenced as an impending event, has not yet begun in earnest. The conflict between the Night's Watch and the Free Folk is still in progress, and Stannis Baratheon still lives, and is currently marching on Winterfell in an attempt to retake the North from House Bolton.