Enmity between houses has been the cornerstone of conflict on Game of Thrones from day one, but there have also been a handful of oddball friendships and alliances that cross between even the biggest enemies. Among those unexpected relationships is the one between Jon Snow, long believed to be a Stark bastard, and Tyrion Lannister, whose house is consistently at odds with the Starks. Despite the friction between their houses, the two misfits have had a mutually respectful relationship for years.
In the very first episode, the two characters first meet, and at first, they seem like a study in contrasts. Young Jon is just getting ready to be sent off to the Night's Watch, and he's clean-shaven, baby-faced, and awkwardly innocent; Tyrion is a drunk, cynical smart aleck. And yet, Tyrion points out that they have something in common: they're both outsiders in their own families.
"Never forget what you are. The rest of the world will not. Wear it like armor, and it can never be used to hurt you," he advises Jon. "All dwarves are bastards in their father's eyes," he adds, underlining their similarity. The duo surprisingly grow a bit closer when Tyrion rides north with Jon on his way to the Wall. Tyrion continues to offer Jon advice, helping him realize that nothing is morally black and white and even rescuing him from some particularly unwelcoming members of the Night's Watch.
By the time Tyrion leaves and Jon continues on to the Wall, it's clear that they're something like friends. "I'm sorry to see you leave," Jon tells Tyrion, before asking him to give a message to Jon's favorite brother, the injured Bran. Tyrion famously notes that he has a soft spot for "cripples, bastards, and broken things," which immediately sets him apart from the crueler members of his family.
Jon and Tyrion don't see each other again for a full six seasons. Jon goes through his adventures with the Night's Watch and the Free Folk, eventually dying, being resurrected, returning to Winterfell, and being hailed King in the North. Meanwhile, Tyrion's conscience keeps developing (although it definitely hits some nasty bumps in the road, notably when he finds out his lover Shae betrayed him), but he eventually breaks away from the Lannisters and instead leaves to pledge his loyalty to Daenerys Targaryen, becoming her Hand of the Queen.
In the third episode of season seven, Jon and Tyrion finally come face to face again when Jon arrives to ask for Dany's help in the fight against the Night King's army. They greet each other with what sound like insults: "The bastard of Winterfell." "The dwarf of Casterly Rock." Turns out, though, it's just highlighting that old thread connecting them as outsiders, almost an inside joke at this point. They greet each other warmly, and it's Tyrion who advocates for Jon to Dany; the fact that Tyrion respects and trusts them both helps smooth the path to an alliance. Since then, they've continued as allies, even when Tyrion's loyalty to Dany has conflicted with Jon's Stark loyalties.
Ultimately, it's the fact that they've always been honest with each other that allows Tyrion to convince Jon of the danger of Dany's increasing tyranny. Tyrion becomes disillusioned first, and finally manages to convince Jon to turn on Dany as well after witnessing the carnage of King's Landing and pointing out that neither Jon nor his siblings will be safe if and when Dany decides they're a threat. At the beginning of the series, the friendship between the outcast Lannister and the illegitimate Stark seemed like just a charming odd-couple pairing, but it turns out to be the relationship that defines the future of Westeros.