It’s understood that the actor and Morgan split last week after four years together.
Now, in one of her first social media posts since news of the breakup came to light, Anderson has revealed that she has bought a new puppy.
“Meet my new gf Stella [sic],” she tweeted on Sunday alongside a photograph of herself cuddling the chocolate brown puppy while reclining on a sofa.
The 52-year-old’s tweet has been liked more than 81,000 times and prompted thousands of replies from fans, many of whom has shared photographs of their own dogs in response.
“OMG! Stella is adorable. I love her coat colour,” replied one person.
“Adorable little munchkin! Such an awesome name too,” added another.
News of Anderson and Morgan’s split comes shortly after season 4 of The Crown debuted on Netflix.
The couple worked together on the show, with Morgan as its writer while Anderson took on the role of Margaret Thatcher.
Anderson spoke about what it was like to work with her then-partner in a recent interview with Harper’s Bazaar.
Recalling being on set in full costume, she said: “I smiled at [Morgan], as me, Gillian, smiling at her boyfriend, and he said, ‘This is Thatcher! This smile is Thatcher!’… And I’m like, no! This smile is me!’”
Anderson went on to say that the couple tried their best to keep things professional.
“For our own sanity, and actually for the benefit of the relationship, we had very clear boundaries,” she said.
“I am not going to comment on the script, but you are not allowed to comment on the performance!”