Their wedding captivated the world, but renowned photographer Mario Testino got a front-row seat to Prince William and Kate Middleton’s engaged bliss when he shot the pair’s official engagement photos in 2010.

Testino shares that the famous photo was captured in a moment of “spontaneous emotion” after he shot the duo for several hours.

“I waited a long time, an hour or two, to make that picture perfect,” reveals Testino. “But I wasn’t totally satisfied.”

It wasn’t until the couple was about to leave that he witnessed the moment of affection he had been looking for.

“They suddenly hugged in front of a radiator,” the photographer explains. “I took my camera and that was the picture that ran everywhere… you could see they were completely in love.”

Testino adds that he’s known the pair was meant to be from the time he met the duo in 2008. “[William was] in love … I knew they would stay together,” he tells Vogue.

will & kate

The Peruvian photographer is a favorite among the royals and was personally selected by Princess Diana for a Vanity Fair shoot in 1997. He was also commissioned to shoot Prince William’s 21st birthday portrait.

On January 14th, Testino received an honorary Order of the British Empire for his services to photography and for his charitable endeavors.