The Great Pendragon
Arguably the First of the Knightly Orders, differing from the ‘battle-brotherhoods’ such as the cult of Mythras, or even the Fenrisget, by upholding honour as their central theme rather than religious observance.
When the wizard Merlin abducted the son of King Uther Pendragon a large body of some thirty or so knights of the realm were implicated in the plot.
For day upon day the staunch knight withstood the pain, and refused to implicate his fellow accused. Eventually the king relented and forgave those knights so accused, realizing the had been pawns in whatever had transpired.
But the group of knights never forgot that one man stood firm, and spared himself no harm to keep them safe. Those thirty knights are now pledged to aid each other as far as they can when any of them are beset by dangers.
Their most recent success was the protection Sir Alain de Chalons from the anger of the Queen when court was held at Sarum in 495 AD