Gillian Anderson and The Crown creator Peter Morgan split after four years together

Gillian Anderson and Peter Morgan have called it quits after four years of dating.

The Emmy-winning actress, 52, and the creator of The Crown, 57, have amicably split, according to a report from U.K. columnist Baz Bamigboye of the Daily Mail. According to Bamigboye, Anderson and Morgan began dating back in 2016, though the former couple never moved in together.

A source tells PEOPLE that the pair — who worked together on the recent season of the Netflix royals series, as Anderson portrayed British Prime Minister Margaret Thatcher — have “highly-demanding schedules.”

A rep for Anderson declined to comment on the actress’ personal life. Morgan’s rep also declined to comment.

Anderson split from first husband Clyde Klotz — with whom she shares daughter Piper, 26 — in 1997, and from second husband Julian Ozanne in 2006. The Sex Education actress was later with Mark Griffiths from 2006 to 2015. They have two children, sons Oscar, 14, and Felix, 12.

Morgan has five children from a previous marriage.

Anderson opened up about filming season 4 of The Crown alongside her then-partner Morgan, telling Harper’s Bazaar in November about their creative agreements.

“For our own sanity, and actually for the benefit of the relationship, we had very clear boundaries,” she told the magazine at the time. They settled on a rule: “I am not going to comment on the script, but you are not allowed to comment on the performance!” added Anderson.

“I’m pretty good at compartmentalizing in my life, period,” she said. “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 that person but be mum.”

To play Thatcher, Anderson explained to Harper’s Bazaar how she “had to get to a point where it’s nothing to do with my opinions of her policies, of her actions.” She said her portrayal is “only about her as a human being and her motivation as a politician and as a mother.”

“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,” she said. “It’s not my world. I’m an actor, I’m not a politician, I’m not a social worker.”