The red capes worn by captains of the Black Banner are said to find their origin in the stories about their first captain Sir George of Whitepeak - founding father of the company: A disgraced knight trying to fight his way back into favours. Along the way he hired some lost thugs an up-to-no-goods to be the pawns in his game.
Wearing a white cape and riding a white horse he pretended to be done with his past transgressions. Still he took all kinds of suicidal missions that the Emperor send him in hope of 'redemption' through the grace of the ruler.
On a fateful day a battle has been fought. A terrible and brutal siege, reckless and unforgiving on both sides. Blood had drenched the white cape and stained his horse and when retreat was issued the disgraced knight saw the terrified faces of his underlings trapped in between formations. Upon seeing the pure mortal dread the knight refused to leave his 'pawns' behind. Instead of retreating he pushed through the enemy ranks on his horse. He rallied them under his banner drenched in black mud and lead them out of the perilous situation.
"You have been pawns of my game but that shall be done now. We shall be knights of our own game. Dishonored or not we shall follow honor of our own and share the spoils and fame. Share it united under the Black Banner! As for honor and redemption cannot be given by anyone else but ourselves."
As the banner is usually the honor and pride of every noble house the Black Banner has forsaken the quest for prestige. It kept taking contracts which seemed beneath a knight to deal with still they would deny tasks they'd deem as too suicidal or not worth fighting for.
Over the last century the numbers of the Black Banner have grown in the hundreds. Their ranks employ footmen, heavy cavalry and logistics. While often being contracted to settle local unrest by intimidation or pure force it is rumoured that occasionally even false flag operations are carried out by this infamous mercenary company.
In honor of their founder the officers of the Black Banner wear dark red capes and blackened armour. Their symbol shows a red horse on a chess board. Not pawns but a versatile force of their own game.