Morning suit
Fashionistas around the world are desperate to know which designer Meghan Markle has chosen for her wedding dress, but what will the groom, Prince Harry, wear? The Queen's grandson could opt for a morning suit – the popular outfit of choice for men at high-society weddings.
Last year, Harry looked particularly dapper at Pippa Middleton's wedding in a grey suit and a yellow waistcoat. Here he is pictured walking to the church ceremony with his older brother Prince William.
A morning suit may also be appropriate given his venue, St George's Chapel at Windsor Castle, which is much smaller than Westminster Abbey and St Paul's Cathedral, but still grand. When Harry's cousin Peter Phillips married his bride Autumn at St George's Chapel in 2008, the groom opted for a formal suit.
Click through to see what other outfits Harry could wear…
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Household Cavalry's Blues and Royals regiment
Harry, however, does have a strong affiliation with the Queen's armed forces. He served in the army for ten years, was twice deployed to Afghanistan and continues to support servicemen and women; he set up the Invictus Games in 2014 specifically to help injured personnel.
It's likely, therefore, that he will opt for a military uniform, rather than a suit, on his big day. Historical advisor Alastair Bruce said: "If he wears a uniform it would probably be that of captain in the Blues and Royals, part of the Household Cavalry Regiment, which was his uniform while serving. With this, he often selects the Army Air Corps light blue beret because he was an Apache helicopter pilot, memorably during his service in Afghanistan."
He added: "The Duke of Cambridge wore the uniform of the Colonel, Irish Guards, because he had recently been appointed to this by the Queen and his wedding, as a future monarch, was a ceremonial one."
The navy blue uniform features gold wire shoulder cords, ornamental gold braiding and red and gold cuffs.
Here, Harry is pictured wearing the uniform with the Army Air Corps light blue beret.
However, The Sunday Times reports that Harry is facing a dilemma. Military sources say it's "a bit naff" in social circles of former guards and cavalry officers to get married in their uniforms, so Harry may not opt for this look.
Royal Marines uniform
The groom could then opt for the Royal Marines uniform. He was given the role of Captain General by the Queen in December. As ceremonial head of the elite unit, Harry is entitled to wear the uniform and insignia. "If I was betting, I would say he'd go for the Marines," Chris Parry, a retired rear admiral, told The Sunday Times.
Prince Philip, seen here in the uniform, held the Captain General post for 63 years until he relinquished the role to his grandson Prince Harry last year.