William Cecil

Lord William Cecil was an advisor to Queen Elizabeth I of England. The Doctor met him at Elizabeth I's coronation. He later tried to tell Evelyn Smythe an anecdote about Cecil, but she kept talking over him about her opinions of Queen Mary I. He was a Protestant (AUDIO: The Marian Conspiracy)

Behind the scenes
In the real world, William Cecil is Robert Cecil's father. While Robert Cecil does mention that his father served under Elizabeth I in The Plotters, no known DWU fiction has explicitly said that his father is William.