Friendships on Game of Thrones can be complicated given the shifting nature of loyalty in Westeros. Your best friend one day could potentially turn on you and stab you in the back (literally) the next day. Because of this, it's rare to see a real, lasting friendship. That's why it's been so much fun watching the relationship between Jon Snow and Tormund develop over the years from enemies to bro-y buddies. After the eighth season's fourth episode, it appears that we might not see Tormund again, so let's revisit the men's shared history.
Tormund and Jon Snow first meet back in season three, when Jon is with the wildlings and pretending to be a traitor to the Night's Watch. The duo get off to a bit of a rocky start, with the wildling Tormund deeply mistrustful of Jon. Over time, the pair come to have a begrudging respect for each other, even though Tormund cheerfully tells Jon that if he's lying to the wildlings, he'll kill Jon himself. Tormund does, however, start joking around with Jon, in particular giving him "advice" and teasing him about his relationship with Ygritte.
Their tentative alliance turns sour quickly, when Tormund orders Jon to kill a captive to prove his true loyalties. Jon is unwilling to do so, and Ygritte does it instead. Convinced by another wildling, Orell, that Jon would betray them, Tormund intends to kill Jon, but Jon is able to fight them off and escape. The duo don't meet again until Jon takes Tormund prisoner during another battle between the Night's Watch and the wildlings. Despite meeting under these violent circumstances, they actually share a genuine moment, when Jon asks Tormund if he wishes to memorialize the dead wildlings and Tormund acknowledges that Jon really did love Ygritte.
After the execution of Mance Rayder, Tormund becomes the new leader of the wildlings, and he cautiously enters an alliance with Jon to work together to eventually fight the White Walkers. Although they face resistance from both of their respective factions, Tormund and Jon are able to convince enough people that the White Walkers are the biggest threat, which becomes even more evident when they have to work together to fight off an unexpected wight attack. Jon's Night Watch brothers consider the alliance a betrayal and they kill him for it.
Tormund is there after Jon is resurrected and welcomes him back to the land of the living in the most Tormund way possible: with a hug and a dick joke. He accompanies Jon home to Winterfell, where he sits on the war council with the Starks and develops an instant crush on Brienne of Tarth. During the Battle of the Bastards against Ramsay Bolton's forces, Tormund leads a charge and personally saves Jon's life at one point. Although he considers Jon his friend at this point, as a wildling, he doesn't join in proclaiming Jon the King in the North.
Following the recapture of Winterfell, Tormund leads a group to man Eastwatch, one of the castles at the Wall, to watch for the Night King's army. Eventually, he joins Jon's expedition to capture a wight. They go their separate ways briefly, but Tormund and his group arrive at Last Hearth, then set out for Winterfell, arriving just in time to warn Jon that the White Walkers are already on their way. He survives the Battle of Winterfell and is last seen departing back to his home north of the Wall; Jon entrusts his direwolf Ghost to Tormund's care, presumably to keep him safe in case Jon doesn't survive the coming battles. If we don't see Tormund again, we'll be sorry, but glad at least that this funny, brave character has survived.