The 33-year-old actress, who plays Queen Elizabeth II, explained how the upcoming series will be a “completely different show”.
Filming for the next series has already been completed and will see the programme move to a different part of the monarch’s reign between 1957 and 1964.
Claire said: “It was amazing. It was completely different, like a completely different show in a way.
“The direction the show has gone in is very different and the period of time is moving on, so it does feel very different.
“It was also lucky because [season one] came out while we were all shooting so it was really lovely that it went down so well.”
She continued to Entertainment Weekly: “It was really lovely for all of the crew and the cast to be like, ‘Woohoo, we’re doing it again!’”
Keeping tight-lipped on future storylines Claire said: “I absolutely fell in love with Jodi Balfour [who plays Jackie Kennedy].
“She’s just brilliant, and Michael C. Hall [who plays Jack Kennedy] is just incredible.
“You really see how amazing it is to put Philip and Elizabeth — their marriage and their world — suddenly into the 1960s.
“You see how the royal family has to start changing and move with the times and realise that things and people are different, and you start to see the evolution of the modern monarchy.”