In 2006, Stewart and Charles were photographed chatting happily at a Buckingham Palace garden party for the charity.

Aside from their charitable endeavors, the king has also bonded with Stewart over their health struggles.

“[Charles] had treatment today, he told me.

Rod Stewart and Penny Lancaster smile with Prince Charles at The Prince’s Trust 35th Anniversary Reception at Clarence House in London (2011)

I went through all that.

I had treatment five days a week.

Like him, I was still working.

Prince Charles, Prince of Wales greets Rod Stewart after the 150th Academy of Music Anniversary Concert in Philadelphia, Pennsylvania (2007)

He’s remarkable,” Stewart enthused at the time, per theDaily Mail.