Is that the sound of abbey bells you hear ringing? The clip-clop of trotting horses pulling a gilt carriage? The roar of a million voices on The Mall in London shouting, "Kiss her, Harry!"
Yes, Prince Harry, 33, the world's most eligible royal bachelor, and his girlfriend of more than a year, have made it official with an engagement, announced by Clarence House Monday.
See Harry and Meghan together: Prince Harry and Meghan Markle photographed together for the first time
Here's what you need to know about the royal engagement:
1. History in the making: Markle will become the first American to be welcomed into the British royal family — ever. She will become a royal duchess, and be titled Her Royal Highness. And she will be the first actress and the first biracial person to marry a ranking member of the royal family.
2. Can Harry marry a divorced woman? Yes, according to the Church of England, which is less dogmatic about divorced people remarrying than it was in, say, the 1930s or the 1950s.
In fact, Markle will not be the first American divorceé to marry a royal, but she's no Wallis Simpson, the infamous American Duchess of Windsor. The Baltimore-bred two-time divorceé married the former King Edward VIII in 1937, six months after he quit his throne for her in 1936. Never forgiven, let alone welcomed, she was denied an HRH title by the royal family.
"There’s just no comparison to Wallis Simpson, who was widely detested and the fact that she had two former husbands living went totally against the rules (then) of the Church of England," Smith says. "Also, people now would be less likely to take exception to the fact that Meghan is an American."
3. Granny gave the OK: Harry needed the permission of his grandmother the queen to marry. The queen, the symbolic head of the Church of England who once had to deny her sister Princess Margaret permission to marry a divorced man, has come a long way since the 1950s: Margaret eventually divorced the man she did marry, and three of the queen's four children are divorced.
4. The stakes are lower: Harry is not going to be king so there is less pressure on him in general. He will soon become sixth-in-line to the throne, after brother Prince William and Duchess Kate's third child is born in the spring.
"The likelihood that he will ever wear a crown is pretty remote at this stage, but he's an exceedingly valuable and popular member of the royal family," says Smith.
5. The right moment: Last month, Harry took Markle to Africa on a romantic safari for her birthday. It's possible, Smith says, he asked her to marry him then, and they've been waiting for the right moment to make the announcement. This is what happened with Will and Kate, who got privately engaged in Kenya in October 2010 and waited until the following month to announce it.
6. Granny's wedding anniversary: The couple may have waited a few extra days to avoid another important date in November. The 70th anniversary of the wedding of the queen, 91, and husband Prince Philip, 96, was marked on Nov. 20.
7. Where will they marry? They could marry in Westminster Abbey, where Will and Kate married and where the queen and Prince Philip married. Or they could opt for the even bigger St. Paul's Cathedral where Prince Charles and Lady Diana Spencer married. But they probably won't choose either, not if they want to avoid the thousands of guests and the billions watching on TV that those royal weddings entailed.
If they want a more low-key, smaller and quieter wedding, they could follow the lead of Harry's father, Prince Charles: He married his second wife, Camilla Parker Bowles, a divorced woman whose ex-husband is still living, first in a tiny civil ceremony in the Windsor town hall, followed by an intimate prayer service in St. George's Chapel at Windsor Castle in 2005.
"They have a little more freedom (to choose) — they could get married in a country church in Gloucestershire, or at one of the churches near Sandringham," the queen's estate in Norfolk, says Smith.
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8. Where will they live? Most likely Kensington Palace, but in bigger and better digs than the small Nottingham Cottage on the palace grounds where Harry currently lives and where Markle stays while visiting him.
Smith believes Harry is likely to get a newly renovated apartment at the palace, which is undergoing extensive new construction, including a two-story facility for staff offices under the Orangery Restaurant on the palace grounds. That would free up more room for a new home for Harry and his bride.
9. What will be their roles? Full-time royals, meaning full-time philanthropy, says Smith. On this, the two have a lot in common: Harry has taken seriously his charity work and his desire to carry on his mother Princess Diana's legacy. And Markle was involved in humanitarian work, including in Harry's favorite continent of Africa, even before she met Harry.
10. The price to pay: For him, it will mean increased media scrutiny, which Harry has already complained about, says Fitzwilliam.
"Harry is deeply resentful of media attention he considers intrusive and there will be a fascination with Meghan's family in the tabloids," Fitzwilliam says.
For Markle, living in the royal goldfish bowl could be a difficult adjustment even for an actress used to media coverage, says Fitzwilliam. "Any echo of 'the prince and the showgirl' or Prince Rainier and Grace Kelly or the Duke and Duchess of Windsor, makes for a media frenzy."
And Markle will have to give up acting, Smith predicts. Her contact with USA's legal drama Suits ends after Season 7, which will broadcast its final six episodes in early 2018.
Also, she'll likely have to adjust her fashion profile to be more like Duchess Kate's, who's not ever been seen wearing ripped jeans at a public event.
"(Markle) would have to be more restrained in how she dresses," Smith says. "She would not have to be as demure as Kate is, but probably ripped jeans wouldn’t cut it."