The Princess of Wales’ brother has penned a memoir about his late cocker spaniel Ella. James Middleton announced his book titled Meet Ella: The Dog Who Saved MyLife during an interview with Tatler. Prince William’s brother-in-law revealed to the outlet that the book documents his relationship with his beloved dog Ella and the journey they went on for 15 years before her death last year.

According to Tatler, James also “offers insights into an extraordinary period of his life with his pet, from trips with Ella up Scottish mountainsides, to royal weddings and his first meeting with his wife Alizee.”

“Writing this book has helped [me deal with the grief I have after Ella’s passing] by enabling me to process the journey that Ella and I went on,” James shared.

“Ella was there at so many of the important moments of my life, including when I met Alizee. Our son was born after Ella passed away so Inigo never got to meet her, but it’s important to me that he knows all about her,” he added. “Another of the reasons that I wanted to write this book was so that I could tell [son] Inigo the story of how I met his mother.”

James showed off the first manuscript in a video shared on his Instagram on March 8. Alongside the post, he wrote: “Many of you have asked me over the years if I would ever write a book, when Ella passed I started writing all of our adventures and memories down as a way of processing the grief. I credit Ella to saving my life when I was eclipsed with Clinical depression, she introduced me to my wife, gave me purpose and loved me unconditionally. I know many of you have your own Ella’s or might be in need of one now and I hope this book will also help us to talk more openly about our mental health, our need for connection, and the way in which the animals that we think we are taking care are always looking after us in return.”

Meet Ella: The Dog Who Saved My Life, which is now available for pre-order, is scheduled to be released on Sept. 26. Octopus publisher Briony Gowlett told Tatler, “There have already been several memorable moments in this book’s life: James Middleton lifting spirits to dizzying heights by bringing five of his six dogs to our pitch meeting; followers lighting up the comments section of James’ Instagram at merely the hint of James writing this book, and me, audibly sobbing on the tube as I read the final chapters.”

“And I expect that’s just the start for this unique memoir,” Briony continued. “What has struck me most when editing Meet Ella, is how little we (the public) really know James, and therefore how lucky we are that he has been so generous and vulnerable in sharing a story that I believe will surprise and chime with readers far and wide.”

News of James’ memoir comes amid his sister Catherine’s recovery from abdominal surgery. Following the Princess’ surgery in mid-January, Kensington Palace said that “based on the current medical advice, she is unlikely to return to public duties until after Easter.”

Her Royal Highness was spotted being driven by her mother Carole Middleton on Monday. The outing marked the first time that Catherine had been seen since Dec. 25. A spokesperson for the Princess brushed off social media speculation surrounding the royal last week, telling HOLA! USA: “Kensington Palace made it clear in January the timelines of the Princess’ recovery and we’d only be providing significant updates. That guidance stands.” The spokesperson also reiterated that the Princess of Wales is “doing well.”