Sarah Ferguson wished her "dear friend" Princess Diana a happy birthday with a touching Instagram tribute, on what would have been her 63rd birthday.

The never-before-seen image offers an intimate glimpse into Diana's life before the world knew her as the People's Princess.

On what would have been Princess Diana's 63rd birthday, ... "Happy birthday to my dear friend, Diana. You were a pillar of light and love. And what a legacy you have left behind.

Sarah Ferguson, Princess Diana. Getty Images (2) Sarah Ferguson is remembering her “dear friend” Princess Diana on what would have been the late royal’s 63rd birthday. “You were a pillar ...

Sarah Ferguson is honoring her dear friend, Princess Diana, on what would've been her 63rd birthday. The Duchess of York, 64, honored the late princess with an emotional tribute on Instagram ...

Happy birthday to my dear friend, Diana. ... public on their late mother’s 63rd birthday. But on ... new statue of their mother in honor of what would have been Princess Diana’s 60th birthday.

Princess Diana would have celebrated her 63rd birthday on July 1. ... “Happy birthday to my dear friend, Diana. You were a pillar of light and love.” the message began.

Born on 1st July 1961, Diana, Princess of Wales, continues to inspire through the efforts of her sons, Prince William and Prince Harry. Her legacy, marked by compassion and dedication to causes ...

Sarah Ferguson is honoring her dear friend, Princess Diana, on what would've been her 63rd birthday. The Duchess of York, 64, honored the late princess with an emotional tribute on Instagram ...

Fergie previously told PEOPLE that she and Diana would have a "Granny-Off" if the previous Princess of Wales were still alive Julian Parker/UK Press via Getty Sarah Ferguson and Princess Diana ...