Much to Pippa Middleton's dismay, all eyes will be on another guest on her big day (if she really did drop the 'no ring, no bring' policy) – and that's Meghan Markle.

The Suits actress girlfriend of Prince Harry, 35, stole the show at Tom Inskip's Barbados wedding in March earlier this year by wearing an Erdem gown plucked straight from the catwalk, and there's no doubt she'll have a similar approach to Middy's nuptials on 20 May.

But Pips shouldn't take the fixation on Markle personally. She's the American divorcee who captured the heart of one of the world's most eligible bachelors and people want to know why. She was the most-Googled actress of 2016, to put it one way.

Markle – who was spotted leaving a swanky spa in London's Soho today (19 May) – landed in the UK on Tuesday and presumably has full access to the wedding after the silly ring-rule backfired and left Middleton looking a bit precious.

The US star, who is also a humanitarian, lead a reasonably low-key life in Toronto, Canada, before becoming one of the world's most sought after celebrities.

What many people don't know is that Markle – who was born and raised in Los Angeles – actually shares the same forename as her onscreen character in Suits. She was born Rachel Meghan Markle, and it's uncertain as to why she adopted her middle name as her first. Perhaps it has something to do with alliteration...

Meghan Markle
Megan Markle attends Misha Nonoo fashion show during Mercedes-Benz Fashion Week Fall 2015 the at Center 548 on February 14, 2015 in New York CityMonica Schipper / Getty Images

Speaking to IBTimes UK ahead of Markle's appearance at Middleton's wedding, royal expert Richard Fitzwilliams said: "Royal watchers will be on the alert for any photographs of Prince Harry and Meghan Markle, his girlfriend since last August and an actress and humanitarian activist.

"When Meghan recently gave up her blog, The Tig, speculation mounted as to a possible engagement with August 4th, her birthday, featuring prominently in the rumours.

"It has been clear the relationship is serious since Harry's open letter about press intrusion made it official last November. It remains to be seen how it develops and if Meghan could commit to royal life and give up her career," he added.