Final preparations are being made for the wedding of the Queen's granddaughter Zara Phillips to England rugby star Mike Tindall.
The couple will exchange their vows in Edinburgh's Canongate Kirk on Saturday in front of their families and friends in a private ceremony, while the reception will be held a stone's throw from the church, in the Palace of Holyroodhouse, the official Scottish home of the Queen.
Lothian and Borders Police have been working with the palace and the city council to ensure the smooth running of the wedding.
Superintendent Ivor Marshall, the commander responsible for security arrangements, said the event is expected to attract significant public interest, despite being a private affair.
Officers have surrounded the kirk since Thursday and barriers line the Royal Mile in anticipation of the crowds. The Queen and Duke of Edinburgh will join Zara's parents, the Princess Royal and Captain Mark Phillips, at the wedding.
Also believed to be attending on Saturday are the Prince of Wales and Duchess of Cornwall, or the Duke and Duchess of Rothesay as they are known in Scotland; the Duke and Duchess of Cambridge; Prince Harry; and the Duke of York and his daughters, Princess Beatrice and Princess Eugenie.
Tindall is likely to have invited some of England's best-known rugby players who are colleagues and friends but the event, in contrast to the recent wedding of William and Kate, will be private. The doors of the kirk will be closed to the media and public.
Festivities are expected to begin on Friday night on the Royal Yacht Britannia, where it is anticipated friends and family will join the couple for pre-reception drinks on board.
The yacht, permanently moored in the historic port of Leith, has served the Queen for 44 years. During that time Britannia carried the monarch and the Royal Family on 968 official voyages, from the remotest of the South Seas to the deepest divides of Antarctica. Zara's parents honeymooned on the ship, cruising the West Indies in 1973.
Zara, 30, and Tindall got engaged last December, having met seven years previously. Tindall's best man is fellow England player Ian Balshaw. Zara's maid of honour has not been announced but could be Autumn, the wife of her brother Peter, who was part of her hen party.