Kate Middleton will miss the society wedding of good friends this weekend as the final countdown to the birth of her baby begins.
Kate, who is more than eight months pregnant, will be staying at home but William and Prince Harry are expected to be among the congregation to watch Thomas van Straubenzee, 30, marry Lady Melissa Percy, 26, tomorrow.
The Duchess's final official public appearance was last weekend when she attended the Trooping the Colour ceremony with other members of the Royal Family.
But with the wedding taking place in Northumberland and her baby due in mid-July, it is possible Kate has decided not to travel.
The groom is a long-time friend of both William and Harry, and the brothers were at the chartered surveyor's London stag do earlier this month.
Mr van Straubenzee travelled to New Zealand with William on a gap year and was reportedly on the phone to Harry when he was mugged in London last year.
It was said that Harry alerted police and went out to find his friend after the ordeal.
Lady Melissa is the Duke of Northumberland's second daughter and she will exchange vows with Mr van Straubenzee in a parish church close to her family's ancestral home, Alnwick Castle, near Newcastle.
Kate's sister, Pippa Middleton, attended the 2011 wedding of the bride-to-be's older sister, Lady Katie, to Patrick Valentine.
Ms Middleton is a friend of the Duke of Northumberland's son, Earl George Percy.
Chelsy Davy, who dated Harry, will be among the 500 guests tomorrow.
The bride will leave Alnwick Castle - which has doubled as Hogwarts in the Harry Potter films - in a restored horse-drawn carriage that is almost 200 years old.
She will wear a Bruce Oldfield dress with flowers by local florist Caro Dickinson, who has also decorated the church and castle.
Lady Melissa, who is a tennis coach, will be attended by her sister and Ms Davy, as well as 12 pages and bridesmaids.
After the 5pm service, a reception will be held in the castle's State Rooms, followed by dinner in a marquee.
There will be fireworks in the evening which the public can watch from the Pastures below the castle.
Soon after the wedding, Lady Melissa's dress will be displayed alongside her sister Katie's wedding dress in The Coach House at Alnwick Castle.