He is best known for his portrayal of Henry Tudor in the TV series The White Queen (2013).
In 2011 Marcus appeared in two episodes of the third season of Misfits as Peter, an avid comic book reader with the power of Future Illustration.
He later appeared in the ten-part BBC One historical drama The White Queen, the 2013 adaptation of Philippa Gregory's novels in The Cousins' War series.
In early April 2014 it was announced that Marcus would play the lead role of Valentine in the Royal Shakespeare Company's production of The Two Gentlemen of Verona.
[2] Marcus described his character as a man "who sort of seems to be running away from something rather than going towards something.