'The Crown' Actress Gillian Anderson and Series Creator Peter Morgan Split After 4 Years of Dating

The Crown actress Gillian Anderson and series creator Peter Morgan have called it quits after four years of dating, PEOPLE reports. While the two never formally moved in with each other, they were very serious. While there has been no comment from either side, one source did tell PEOPLE that the two have "highly-demanding schedules."

Anderson portrayed British Prime Minister Margaret Thatcher in the popular Netflix series, and spoke with Harper's Bazaar about how the two managed to work on set together and keep their personal and professional lives separate. While it's a challenge, she explained that they had to put up boundaries in order to keep their relationship healthy.

"For our own sanity, and actually for the benefit of the relationship, we had very clear boundaries," she said at the time saying they had very clear rules. "I am not going to comment on the script, but you are not allowed to comment on the performance!" Anderson recalls a few times where she's had to turn her mood around at the flip of a switch and says she's really good at "compartmentalizing" because of her lifestyle and how she grew up.

"I'm pretty good at compartmentalizing in my life, period. I think I learned that quite young, being a young mother, in a really intense TV series where it was either full-on on set, or I was in my trailer having to shut the door and no longer be the person but the mum," she added. The two were able to work together without butting heads all the time, but she also had to go into a mental place herself when bringing to life a character like Thatcher.

Anderson "had to get to a point where it's nothing to do with my opinions of her policies, of her actions," but her portrayal is "only about her as a human being and her motivation as a politician and as a mother." She continued, "I feel like I have an opportunity as somebody in the public eye to draw attention to things, but I don't comment. I don't offer my opinion on social media on a regular basis. It's not my world. I'm an actor, I'm not a politician, I'm not a social worker."

Anderson was previously married to Clyde Klotz, with whom she shares daughter Piper, 26. The two divorced in 1997. She then got remarried to Julian Ozanne but they divorced in 2006, but later got together with Mark Griffiths from 2006 to 2015. They share sons Oscar, 14, and Felix,12, together. Morgan has five children.