Which actress plays Patricia Campbell in season 2 of The Crown?

Gemma Whelan plays Patricia Campbell in season 2 of The Crown.

Patricia Campbell is presented as a secretary who works with Lord Altrincham, the writer whose criticism of Queen Elizabeth II challenges the traditional style of the monarchy. Campbell types his editorial, helping connect the private drafting of his argument with the public controversy that follows.

The storyline appears in “Marionettes,” the season's fifth episode, which fictionalizes the 1956 criticism of the Queen by John Grigg, who wrote under the name Lord Altrincham. The real controversy concerned the monarchy's public image and its distance from ordinary people. Campbell is a supporting historical character, so viewers sometimes confuse Whelan with the better-known season-two performers Vanessa Kirby, Michael C. Hall, or Jodi Balfour.