Rumours that have circulated for years regarding the relationship between Princess Diana and Sarah “Fergie” Ferguson have finally been put to rest.

The Duchess of York said she had an unshakeable bond with Diana, quelling rumours they fell out before her tragic death.

“We promised each other we would always be together – there was never any daylight between us,” the 61-year-old told People magazine. “But everybody wanted that because we were so strong together. People want to break something so strong.”

Diana and Fergie first met as teenagers, before going on to marry two of Queen Elizabeth II’s sons.

“We were best friends from when she was 14 and I was 15,” she told the outlet, sharing that her nickname for Diana was “Duch”.

“She taught me so much of public life,” she said. “She was so brave. We used to have the most incredible time together.”

Fergie and Prince Andrew were married from 1986 until 1996. They share two daughters: Princess Beatrice, 32, and Princess Eugenie, 31.

“[Diana] adored my girls,” Ferguson told the outlet. “She adored [her] boys. This would be her haven. Her heaven.

“She would be very proud of her sons and their wives,” she said. “And she would be just like me, obsessed with her grandchildren. Because that’s what she loved … If she were sitting with me right now, I know she would say, ‘I am so proud of both of my boys and the wonderful wives they have chosen.’ Because each has got her own voice.”

This article originally appeared on Over60.