Britain's Prince George celebrates his sixth birthday. Picture: Reuters

Prince George had a football-themed birthday bash. 

The young royal - who is the eldest child of the Duke and Duchess of Cambridge - reportedly invited his entire school class at Thomas Battersea in South West London to his sporty party at Kensington Palace to help celebrate him turning six. 

According to HELLO! magazine, Duchess Catherine and her husband Prince William - who also have children Princess Charlotte, four, and Prince Louis, 15 months, together - arranged for the party to take place after school so that George could celebrate his birthday with his pals from school before the end of term. 

Although George seemingly has a strong love for football, he was given a private tennis lesson by Swiss champion Roger Federer, who is his "favourite player" at the moment, after his match at Wimbledon at the beginning of July. 

Federer - who has four children of his own -  said of the royal's skills: "At that stage it's all about just touch the ball, it's already good. Same with my boys. I think I have a little advantage that I actually spent some time, you know, with him.

"I'm the only player he's ever met. 

"Then you have a little head start in who is your favourite player."

And he hopes he will keep up the court sport.

He added: "I love to see that they're into tennis or into sports ... his mum has always enjoyed their tennis ... I hope that he'll still say the same in a few years' time."

Prince William previously revealed he wants his children to get into sports.