That's the king on his throne, Peter Ironfoot. He lost his foot at the Battle of Everwick, but carried on through the pain until he had won the fight, and put more heart into his men with one foot than he did with two. After the battle, he had an iron foot made to replace the one he had lost.

When the battle was won and the enemy defeated, King Peter showed great mercy, for instead of acting the tyrant, he offered to marry Princess Ellen of Everwick, who had taken his fancy, so that the two kingdoms might be forever joined. 

He made Ellen's father swear him fealty, gave him many gifts of gold and silver, and vowed that from that day forth, the kingdoms of Lindensea and Everwick would be not only friends and allies, but also kinsfolk.

That's the official version of how Bernard's parents were married, as told by Mrs Bennett in Raven and Rue. This is the true story ...