Kate, Duchess of Cambridge and Meghan, Duchess of Sussex, right, sit in the Royal Box on Centre Court. (Andrew Couldridge, Pool via AP)

When Meghan Markle joined the Royal Family there was speculation that Kate Middleton would resent having to share the limelight with another beautiful woman.

But during their first day out together without their husbands, a new friendship was clearly born – even while Meghan’s pal Serena Williams was losing the Wimbledon ladies’ final.

Kate Middleton and Meghan Markle in the Royal Box. (Picture: Reuters)

The glamorous new BFFs – best friends’ forever – showed very different styles. The Duchess of Sussex displaying effortless Hollywood chic in her eye-catching flares. She also wore a crisp poplin striped shirt by Ralph Lauren – whose PR director, Violet von Westenholz, is said to have set up a blind date between the actress and Prince Harry.

Meghan, Duchess of Sussexcrisp poplin striped shirt by Ralph Lauren. (Picture: Reuters)

The Duchess of Cambridge preferred the classic Middle England look of a draped silk monochrome dot dress by her friend Jenny Packham.

Duchess of Cambridge wears a draped silk monochrome dot dress. (Picture: Reuters)

Before the ladies’ final, the sisters-in-law met the ball-boys and girls and watched the exciting conclusion of the men’s semi-final between Rafa Nadal, of Spain, and Serbian Novak Djokovic, which had over-run from the previous evening. After world No 1 Nadal won a game, analysis by a lip-reader revealed that the former Suits star said to Kate: ‘The way he moves is fabulous.’

Rumours of a frosty rivalry proved unfounded, with Kate, a patron of the SW19 club, at one point asking Meghan: ‘Are you OK?’ The pair giggled throughout the match and cheered as Djokovic won.

Celebrities rubbing shoulders with the duchesses in the Royal Box included Harry Potter actress Emma Watson, Line Of Duty’s Thandie Newton, James Norton of McMafia fame and actor Sir Mark Rylance.

Emma Watson. (Picture: Reuters)

New mum Miss Williams could not complete the mother of all victories just ten months after giving birth and was beaten in straight sets by 11th-seeded German Angelique Kerber.

Just reaching the final was an incredible feat for the 36-year-old, who almost died and was left bedridden for six weeks following the difficult birth of daughter Alexis Olympia last year.

Miss Williams, who became friends with Meghan after meeting her at a charity football match in 2014, was a guest at her wedding to Harry in May.

Before the match, she said: ‘We’ve always had a wonderful friendship. Every year for a couple of years she comes out to Wimbledon and supported me. Now she’s supporting me in a different role. But our friendship is still exactly the same.’

Serena Williams. AP Photo/Tim Ireland

She added: ‘If there was a Wimbledon royalty, I would like to believe I would be Wimbledon royalty because I’ve done pretty well here in the past.’

Afterwards, when asked how she would tell the story of playing in front of two duchesses to her daughter, Miss Williams replied: ‘I’ll probably change the ending.’

The tournament has not a been a complete disappointment for British fans, with Alfie Hewitt and Gordon Reid winning the men’s wheelchair doubles final yesterday and 16-year-old Jack Draper reaching today’s boys’ final against top seed Chun Hsin Tseng, of Taiwan.