Any day now, the invitations will be dropping into mail boxes across Britain and further afield. A select few will be receiving not one, not two, but three requests for their company at the events on April 29.
The invitation to the marriage service at Westminster Abbey will be on stiff white card with gold edging and will be dispatched by the Lord Chamberlain, one of the Queen's officials. It's a position which has been around since the early Middle Ages. When guests were summoned in 1947 to the wedding of the then-Princess Elizabeth, the wording on the card read, "The Lord Chamberlain is commanded by Their Majesties to invite..."
Sixty-four years later, roughly 1,800 people will receive such an invitation. However, one is unlikely to be on its way to 1600 Pennsylvania Avenue. President Obama will have to save his congratulations, and indeed his present for the couple, for when he next visits the UK. His wife has already given this advice to Prince William and Kate Middleton: "Enjoy. Love each other. Have fun and go on a great honeymoon."