Sarah Ferguson led birthday tributes to her “dear friend,” Princess Diana, on what would’ve been the late royal’s 63rd birthday.

Diana was born on July 1, 1961, and was 36 when she died in a car accident in Paris on Aug. 31, 1997. Prince Harry was just 12 at the time of his mother’s death, while Prince William was 15.

“Happy birthday to my dear friend, Diana. You were a pillar of light and love,” Ferguson, the former wife of Prince Andrew, wrote in an Instagram post on Monday.

“And what a legacy you have left behind. I will forever remember our laughter and the kindred, kind spirit I found in you,” she added. “I am sure you are watching over us always. Rest in peace my friend.”

Ferguson, also known as “Fergie,” included a photo of herself and Diana from September 1990 in the post.

The Duchess of York has spoken out about her friendship with Diana, which was made all the more complicated at times by tabloids pitting the two against each other.

“In the ’80s, it was Diana looking beautiful, and there was fat, frumpy Fergie,” Ferguson told People magazine in 2021, explaining that she and Diana “were positioned as saint and sinner” in the eyes of the media.

The two also had a famous falling out before Diana’s death, though Ferguson has insisted they were on the path to reconciliation.

“Because we were like siblings — actually, we were fourth cousins and our mothers, who went to school together, were also best friends — we rowed,” she told Harper’s Bazaar back in 2007.

“And the saddest thing, at the end, we hadn’t spoken for a year, though I never knew the reason, except that once Diana got something in her head ... I tried, wrote letters, thinking whatever happened didn’t matter, let’s sort it out,” Ferguson added. “And I knew she’d come back. In fact, the day before she died she rang a friend of mine and said, ‘Where’s that Red? I want to talk to her.’”