Rodrik Cassel
Winterfell's master-at-arms, a stout old knight with famous white whiskers who trained every Stark child to hold a sword.
The fuller tale
Ser Rodrik is the North's institutional memory of how to fight — a stout old knight with magnificent white side-whiskers he tugs when thinking, master-at-arms of Winterfell, and the man who put the first practice sword into the hand of every Stark child of two generations. He served through Robert's Rebellion and the Greyjoy Rebellion, buried most of his own family along the way, and settled into the job the tale finds him doing: turning boys into swordsmen without letting them notice they are being turned into decent men at the same time.
The war promotes him past the training yard. With Ned south and Robb marching, Rodrik becomes castellan of Winterfell in all but title — the armed adult in a castle of children, hostages and clerks. He escorts Catelyn south on the mad business of arresting the Imp, sits in judgment beside little Bran on the petitions of a lord's absent justice, and answers each new fire — reavers at Torrhen's Square, treachery at every gate — with the same unglamorous diligence he taught in the yard. He is what the North's depth of bench actually looks like: not a legend, just a knight who never once failed to saddle up.
His last relationship is his bitterest: Theon Greyjoy, whom he trained for a decade, takes Winterfell by trick while Rodrik is drawn away — and the old knight must besiege his own castle, held by his own pupil, with the boys he swore to protect inside. The tale gives him no good move on that board, and watches him play it anyway.
The page and the screen
The two tellings kill the same man at different gates. In the show, Rodrik is captured when Winterfell falls, spits on Theon in the courtyard, and is executed by him there — Bran begging, the Bolton man Dagmer goading, and the deed done so badly it becomes the measure of everything Theon has broken in himself. In the books, Rodrik never gets back inside: marshaling the North's home levies to retake the castle, he is betrayed outside its walls when Ramsay Bolton — riding as his ally — turns on his little army and butchers it, the old knight included, in the slaughter Theon watches from the battlements. Show viewers remember Rodrik's death as Theon's crime; readers file it under Ramsay's, with Theon merely damned as an accessory. Both versions agree the whiskers deserved better.
Where they stand, season by season
Their fate — if death has found them, it is written here. Open at your peril.
The show: Executed at Winterfell (S2·E6)
The books: Killed in the sack of Winterfell (ACOK, ch. 67)
Winterfell's old master-at-arms rode home into Theon's occupation and spat at his former ward. Theon's first execution was botched and butcherly — it took four strokes and a kick — but Ser Rodrik died as unbending as he lived.
The show gives Ser Rodrik the uglier, more intimate end: dragged before the captured Winterfell's gate, he tells Theon to his face that the boy is truly lost, and Theon — dared by his own men to prove his rule — takes his old teacher's head personally. He botches it. The sword is wrong, the stroke is wrong, and it takes four hacks and a kick to finish what a headsman does in one, while Bran screams and the household watches. In the books, Rodrik dies outside the walls he was trying to save, cut down when Ramsay's Dreadfort men fall upon his relief force mid-parley — a betrayal so complete the books deliver it secondhand, through Theon's horrified memory. In both, his death marks the moment the North's old certainties stop applying: the yard's rules were fair, and nothing after him is.