Prince Harry and Meghan Markle will parade through Windsor in a horse-drawn carriage after saying ‘I do’ as the route has finally been revealed.

The royal couple will tie the knot at St George’s Chapel, Windsor Castle on Saturday, May 19. And with less than 100 days to go, preparations are in full swing.

Around 100,000 people are expected to descend on the town to catch a glimpse of the couple.

The 45-minute service will take place at noon. Archbishop of Canterbury Justin Welby will marry the couple and the Rt Rev David Conner, Dean of Windsor, will conduct the service at the 15th century chapel. The couple will say their vows before leaving from the West door of the chapel.

They will then parade through Windsor in an open-top carriage, probably leaving from the Henry VIII Gate, right down Castle Hill, turning left at Victoria’s statue, along High Street, right into Sheet Street, past Victoria Barracks and up King’s Road, to Albert Road and left into the final stretch of the Long Walk and in through the castle’s Cambridge Gates for a reception in St George’s Hall.

Prince Charles will host a party in the evening, as he did for Prince William and Kate Middleton in 2011.

Invitations are expected to be dispatched soon to some 800 guests.

US president Donald Trump is not expecting a coveted invite to arrive in the post, but some of those who might be include former American leader Barack Obama, tennis star Serena Williams and Ms Markle’s Suits co-stars Sarah Rafferty, Patrick J Adams and Wendell Pierce.

In 2011, Prince William and Kate Middleton’s invites – traditional white cards, gilded along their edge with gold, with the royal cypher – were sent out around 10 weeks before their wedding.

Harry and Ms Markle have around 14 weeks until their big day.

They may opt for the traditional royal invitations on thick white card, which begin with the words “The Lord Chamberlain is commanded by The Queen to invite ...”.

But Ms Markle is an expert calligrapher, who used to craft invitations for celebrity weddings, so she may decide on her own alternative style.

The Lord Chamberlain’s Office at Buckingham Palace is responsible for William is expected to be Harry’s best man, or perhaps jointly take on the task with one of Harry’s childhood friends. He has already joked that he is yet to be asked by his younger brother, and as President of the Football Association he may well have to attend Wembley for the FA Cup Final later that day.

Prince George and Princess Charlotte look set to be page boy and flower girl.

But Ms Markle may also choose some grown-up bridesmaids from her close set of friends – most likely Canadian stylist Jessica Mulroney and Indian actress and philanthropist Priyanka Chopra.

Ms Markle could even pick a best woman.

Ms Markle is going to be both baptised and confirmed in the Church of England ahead of the wedding.

She can choose to be fully immersed in water in a special pool at her christening, but it is more likely she will opt for a small trickle of water being poured on her head at a font.

The baptism and confirmation, expected to take place privately, can happen on the same day.

Shortly before her wedding, Kate was confirmed in a secret service at the Chapel Royal in front of William and her family.

For the service Harry and his bride-to-be will also be deciding on their chosen music, hymns and prayers for the traditional ceremony.

The couple will also have to settle on their vows, but Miss Markle, who was a UN women’s advocate, may opt not to ‘obey’ her prince.

They will probably choose the Series One (1966) Book of Common Prayer ceremony, just as William and Kate did, which allows the bride to drop “obey him” and “serve him” from the religious proceedings.

Harry also has to decide whether to wear a wedding ring. William does not wear one.

As for the dress, Ms Markle’s stylist and close friend Jessica Mulroney runs a bridal store in Toronto so is said to have been helping the bride choose her gown.

Sir Elton John, who has a mansion on Crimp Hill, Old Windsor, has reportedly cancelled two of the dates of his Las Vegas residency to attend the royal wedding, amid speculation he could also be performing. Ed Sheeran, Sam Smith and grime artist Stormzy have also all volunteered, but no acts have yet been confirmed.

As far as security in the town is concerned, plans are already being put in place for policing the grand royal occasion, with thousands of people expected to descend on the town to catch a glimpse of the bride and groom.

It looks likely that the car park on Home Park public that will have been laid for the Royal Windsor Horse Show the week before will be used for the thousands expected to turn out.