According to royal expert Kate Nicholl, there's a reason for that.
"[Harry is] incredibly close to his grandfather and, being 96, Harry thought it was a great thing to [have] the wedding sooner rather than later, so his grandfather could be there, fit and healthy," Nicholl told Entertainment Tonight.
Harry's grandfather, the Duke of Edinburgh, spent two days in hospital earlier this year to receive treatment for "an infection arising from a pre-existing condition." His hospitalization came just one month after he announced his plans to retire in the fall, after 65 years of service. His decision to step down, however, was not due to his health.
"I think he is retiring now in order to have a few years of retirement and I think the timing is thought through," Gyles Brandreth, an English broadcaster and a friend of the duke's, told BBC News in May. "It's 70 years this autumn since he became the consort of Princess Elizabeth and then the Queen — so, after 70 years, I think he feels probably he has done his stuff."
Harry and Markle will wed this spring at St. George's Chapel at Windsor Castle, which is one of the residences of the Queen.
Plus, the Duke and Duchess of Cambridge are expecting their third baby in April, so Harry and Markle's May wedding date was likely strategically chosen so that it wouldn't interfere with the newborn's birth.
While six months might seem like a short time between getting engaged and getting married, it's important to note that Prince William and Catherine had very similar timing. The royal couple announced their engagement in November 2010 and tied the knot at Westminster Abbey in April 2011.
Additionally, Harry and Markle began dating over a year ago, which is why the newly engaged actress wouldn't call their relationship a "whirlwind" romance.
"I don't think that I would call it a whirlwind in terms of our relationship, obviously there are layers attached to how public it has become," Markle told BBC's Mishal Husain. "We had a good five or six months of just privacy, which was amazing. I think we were able to have so much time just to connect and we never went longer than two weeks without seeing each other even though we were obviously doing the long-distance relationship. We made it work."
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