"Bending the knee" is a formal act of submission to a king or lord, a recognition of authority and a demonstration of fealty. It is common for surrendering parties to bend the knee after being defeated in a war or rebellion; in return, the ruling king or lord will usually treat those that bend the knee with leniency - e.g. Torrhen Stark, the King in the North, bent the knee to Aegon the Conqueror to spare the lives of the people of the North, and was named Lord Paramount of the North by Aegon in return.