Alright, I’ll tackle this with the caveat that the phrase 'Guardian King of the North' isn’t a strict, universal title—different novel series treat northern rulers differently. If you’re thinking of 'A Song of Ice and Fire' (which many call 'Game of Thrones' in adaptation), the closest thing is the 'King in the North' or the Warden of the North from House Stark. Robb Stark was proclaimed King in the North by the northern lords during the War of the Five Kings, and later, in a different political moment, Jon Snow receives that same acclamation. They function as guardians of the North culturally and militarily—protecting the realm from southern politics and, in the broader narrative, from threats beyond the Wall.
I love how the title carries weight depending on who holds it: Robb’s youthful, honor-bound kingship contrasts with Jon’s grim, reluctant leadership. Both embody that northern guardian vibe—stubborn, loyal, and fatalistic—and that’s why fans keep debating which of them truly deserved the crown; I lean toward Jon for the tough choices he made, but Robb’s earnestness still hits hard for me.