The first was early in 2004 when she played Mary, Queen of Scots in the BBC drama Gunpowder, Treason and Plot.
During filming for the programme she said: "When I was learning lines, I had to be more careful about learning them in English. I had to make sure the pronunciation was correct as well as understanding the meaning."
Clemence, who was born in Paris, first got her interest in acting from her father, a theatre director and actor. And, after finishing school when she was 16, went on to get an agent and study acting.