It will go down as an iconic image of 2018 – Prince Harry and Meghan Markle sitting together on some steps shortly after they were pronounced husband and wife.

But the black-and-white image was a complete fluke amid an intense and high-pressure environment, royal wedding photographer Alexi Lubomirski has revealed.

Speaking to the BBC, Lubomirski explained he was given just three-and-a-half minutes to photograph the couple alone.

“We went out there and had about three-and-a-half minutes to take some quick shots because everything was running like clockwork,” he said.

“It was just one of those magical moments when you’re a photographer and everything falls into place. I said ‘just before you go [inside], sit on those stairs.’

“And she just slumped between his legs and there was this moment where they were just laughing because they were exhausted and thinking finally it’s all over,” he recalled.

“It was one of these beautiful moments.”

Lubomirski, a Mario Testino protégé who also took the couple’s engagement photos, described it as “an incredible honor and privilege” to photograph the royal couple.

“To say that it was a big assignment would be putting it mildly,” he said.

“This has been a beautiful chapter in my career and life, that I will happily never forget.”

See all the wedding photos Prince Harry and Meghan Markle released here.