Kate and Pippa Middleton's Wimbledon style over the years

Pippa Middleton, the younger sister of pregnant Kate Middleton, has had a love affair with tennis since the age of eight when she first attended the Wimbledon championships.

"During this first trip I acted on my childish tennis dreams and bought myself a postcard of the women's championship trophy, on which I wrote, 'I will win this one day,' with my signature below," recalls Pippa in Vanity Fair, where she is contributing editor.

Over the next two weeks of the world-famous tournament, Pippa and Kate are expected take their seats courtside, cheering on their favourites from the royal box.

Pippa, donning a pretty blue dress and jacket, was spotted at the opening game on Monday, enjoying the on-court action alongside younger brother James Middleton. The siblings happily chatted to spectators around them, including Denise Lewis and Princess Michael of Kent.

HELLO! Online takes a look back over the years, and admires how the chic Middleton sisters have graced the Wimbledon courts with their fashionable presence.