He added: “I am quite pleased about it because, being honest with you, the idea of spending six seasons on anything makes me feel a little jitter.
“I think if they pull off this feat of TV where every two years they change the cast — what a wonderful thing to be part of.”
Besides Menzies taking the role on from Smith, there have wholesale changes in the rest of the cast.
As mentioned earlier, Oscar-winner Olivia Colman will play The Queen.
Helena Bonham Carter replaces Vanessa Kirby as Princess Margaret while Josh O’Connor plays a grown-up Prince Charles, taking over from Billy Jenkins.
The Crown season 3 is released on Netflix on Sunday, November 17.