The decision to cast James Norton in King and Conqueror was made logically rather than creatively.
Harold of Wessex and William the Conqueror are the two protagonists of Studios’ forthcoming King and Conqueror. Although Norton was the star of The Nevers at the time, he still wanted to play William.
In order to avoid any contract conflicts, HBO informed the actor that he might appear in the new series, but in a role that would only last a few seasons.
Since William is portrayed by Game of Thrones actor Nikolaj Coster-Waldau, the War & Peace star was chosen to play Harold of Wessex, who met William in person at the Battle of Hastings in 1066.