The Winds of Winter: Who wrote the letter that killed Jon Snow?
Did Stannis Baratheon write the Pink Letter?
The letter states that Stannis Baratheon was defeated and killed after seven days of battle. However, Stannis is still alive at the end of the book and in the preview chapters for The Winds of Winter. It is possible that Jon’s last chapter in Dance takes place later than those, since Martin mixes up the timeline sometimes. But this is unlikely, because Martin has said that we will see the battle at Winterfell in the beginning of the next book. This likely means that Stannis is still alive when the pink letter was written, and the bit about him being dead is a lie.
Narratively, it would also be frustrating and lazy for Stannis to die “offscreen” in so anticlimactic a fashion, particularly when there’s some reasonable foreshadowing that he will win the battle at Winterfell despite being in a pretty bad situation. His army is snowed in and starving, but he is confident about the Bolton attack on his position. “Let them come,” he says. “We hold the ground, and that I mean to turn to our advantage.”
According to a fan theory called The Night Lamp, Stannis will use the tower in the snowed-in village to draw the Bolton army onto a frozen lake, similar to a lighthouse luring ships to shore. Turning the ground to his advantage could mean breaking the ice while the Bolton army is on the lake and plunging them into the frozen water.
So Stannis is still alive and we know that he is in a bit of a tight spot. It is not out of the realm of possibility for Stannis to write the letter to Jon hoping that Jon would ride south with more men. When Jon arrived, he would likely help Stannis defeat the Boltons and become the Lord of Winterfell, just like Stannis wanted in the first place.
However, manipulation and deceit are not really Stannis’ strong suits. It isn’t in his nature to lie to others to get his way, and it’s almost impossible to imagine him pretending to be someone else, even to write a letter. It would also be a huge gamble for him to rely on Jon bringing more men to help him win.
There is another candidate in the north that could make sense though, and we know he is already working to restore the Starks to power.