Tennis fans around the world will have Wimbledon on their minds as we head into the week of June 29th.

The annual tennis tournament, which would've run June 29 - July 12, was cancelled for 2020 due to the COVID-19 pandemic. Over the years, Prince William and Duchess Kate have counted themselves as attendees of the finals event.

But Kate Middleton actually had another notable absence from the tournament back in 2013.

THROWBACK: See Duchess Catherine Present Wimbledon Trophy in 2019

Duchess Catherine pregnant with Prince George in 2013.

Observant royal fans will recall that Prince George was born in the summer of 2013. Kate's pregnancy overlapped with Wimbledon, and was the reason she missed the tournament that year!

Duchess Catherine recalled Wimbledon absence in 2017 film

As Hello! reports, the Duchess revealed the story behind her absence in the 2017 BBC documentary, Our Wimbledon

"I was very heavily pregnant with George so I wasn't able to turn up," Kate said in the documentary. "But you had a great excuse!" the film's presenter replied.

Kate responded: "I know but even still, I sort of was there… 'maybe I could go' but the doctors were like 'definitely not.' I wrote to [Andy Murray] afterwards saying 'sorry for not being there, but huge congratulations'," she recalled.

Andy Murray won the men's singles title that year, becoming the first British tennis player to do so since 1936.

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Prince George was born just after Wimbledon in July 2013

In 2013, Wimbledon ran June 24 - July 7. Prince George, who's now 6 years old, was born just a few weeks after, on July 22. The Duchess had already concluded the last of her scheduled royal duties on June 15, at Trooping the Colour, and she was advised not to attend the sporting event.

Nevertheless, the Duke and Duchess of Cambridge were in attendance when Murray repeated his unique British tennis feat as Wimbledon champion in 2016.

Kate Middleton and Prince William attend Wimbledon in 2015.

The Cambridges no doubt join the sporting world in looking ahead to Wimbledon 2021. The 134th Championships, which were to play in 2020, have instead been rescheduled for June 28 to July 11, 2021.