The best-kept secret: What have Meghan and Harry named their son?

With Prince Harry and Meghan Markle about to introduce three-day-old Baby Sussex to the world on Wednesday during a photocall in Windsor, the current question of the year is: What will the Duke and Duchess of Sussex name the royal baby? Royal fans have been speculating wildly, but we're looking to British betting houses to see which names we'd put our money on! Just hours before Meghan and Harry confirmed their baby's birth on Instagram on Monday, bookies had closed all bets on the baby's due date. Will they be just as accurate when it comes to the name of Queen Elizabeth II's eighth great-granchild?

Betting company Ladbrokes wagers that Arthur, one of Prince Charles' middle names, is the front-runner. Royal fans also think Princess Diana's maiden name, Spencer, might be a great choice for the very modern Meghan and Harry

The front-runner according to Ladbrokes is... Arthur! In addition to being the name of an adorable children's cartoon character, it's also one of Harry's dad Prince Charles' many middle names. It's also Prince William and son Prince Louis' middle name, which makes it a very likely contender.

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Another top choice, Albert, is one of Harry's middle names. It's also the name of the royal baby's great-great grandfather, the Queen's beloved dad George VI – immorailized in the movie The King's Speech – who was called by his birth name Albert, and nicknamed "Bertie", before he became King. The 6/1 odds for that moniker are tied with Philip, which is of course, the name of the Queen's husband, the Duke of Edinburgh.

Albert is the name of Monaco's Prince, but is also a family name belonging to the Queen's beloved dad, seen here with the monarch in 1946

The betting company is also wagering that James – a classic British name belonging to, for example, Kate Middleton's brother James Middleton – could be the choice, edging out Alexander, Alfred and Thomas.

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There's a possibility Meghan and Harry might named their little man after grandpa Prince Charles, or even after dad himself, whose birth name is Henry. (Harry, Jr sure would be pretty cute!) But could we see a surprise nod to Prince Harry's adored mom, Princess Diana? Diana's maiden name Spencer, is in the running with 14/1 odds, since many think the modern royal couple will opt for a non-traditional name.

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Given how Prince Harry and Meghan are definitely doing things their own way – from announcing the birth on Instagram to keeping the birth location a secret – we are sure there are some baby name surprises in store!