Dame Helen Mirren, who received a BAFTA Fellowship from the Duke of Cambridge at London's Royal Opera House, tells PEOPLE, "He was so great backstage – so lovely. He was very easy, very relaxed."
The Queen star – who won the Best Actress of 2006 Oscar for playing William's grandmother, Queen Elizabeth II – added that the future king represents a new kind of relaxed and fun-loving royal. (William seemed to prove this point by posing for selfies on the BAFTA red carpet and even giving British rapper Tinie Tempah a high five during his performance at the awards show.)
"I don't mean this rudely, but you would never think that he was a prince, which to me is the biggest compliment you can make," Mirren said.
"I just felt as though I was meeting a very nice chap. There was no prince-ness about him at all."
As for being made a Fellow of the British Film Academy – of which Prince William is president – Mirren added: "I didn't realize just how big a thing it was to receive a fellowship. They don't give it out every year. So now I am just completely overwhelmed."