Charles Spencer is marking a major personal milestone.

On Thursday, Oct. 16, the 9th Earl Spencer and younger brother of the late Princess Diana shared that he had reached “6 months without alcohol.”

“Never felt better,” Spencer, 61, wrote, sharing a photo of himself holding a non-alcoholic Guinness beer.

He then shouted out his girlfriend, Cat Jarman, for “your quiet and thoughtful support in this happy transformation.”

Jarman, whom Spencer began dating last year following his divorce from his third wife, Countess Karen Spencer, shared his post and captioned it with her own support.

“Incredibly impressed & proud of you, @cspencer1508!” she wrote. “You have such admirable willpower and resilience. 🩷”

She went on to engage with a commenter who lamented they had a hard time finding a non-alcoholic wine that they liked. “There seem to be a lot of quite good sparkling ones, and we quite like Zeno and Oddbird’s offerings,” Jarman, 43, shared.

Spencer and Jarman, a Norwegian archaeologist, reportedly met when Jarman was searching for the remains of an ancient Roman villa on the grounds of Spencer’s ancestral home, Althorp, for a documentary. They now co-host a podcast, The Rabbit Hole Detectives, alongside broadcaster Rev. Richard Coles, and co-published The Rabbit Hole Book last year.

Spencer announced his third divorce in June 2024, sharing that the news made him “immensely sad.”

“I just want to devote myself to all my children, and to my grandchildren, and I wish Karen every happiness in the future,” he said.

The couple shares one daughter, named in part for her late aunt: Lady Charlotte Diana, 13. Spencer also has four children with his first wife, Victoria Lockwood, and two with his second wife, Caroline Freud.

In addition to the tragic loss of his older sister in her 1997 car accident, Spencer also recently revealed that he suffered a great trauma during his childhood.

Last year, he published his memoir, A Very Private School, in which he shared that he had been sexually abused as a child by a female staff member while at boarding school.

Spencer said that reliving that trauma deeply affected him and exclusively spoke to PEOPLE about his wife’s support during the five-year writing process.

“I think it was very challenging for her to have a husband going through what was essentially four and a half years of the most profound therapy with very difficult undertones to it,” he said. “I think she always hoped I would come out happier and healthier. And that seems to be the case, very much.”