Philippa Middleton, Maid of Honor
Imagine the pressure. Not only do you have to throw your sister a bridal shower and help plan her wedding, but the whole world is watching your every move. Kate Middleton's 27-year-old sister Pippa has a big job ahead of her. On the plus side the reception is bound to be packed with tons of eligible (read: royal!) bachelors.
Prince Harry, Best Man
Prince William broke with tradition when he asked his 26-year-old brother to be his best man—royals usually appoint a "supporter." Prince Harry's risen to the challenge, saying his speech on the wedding day won't embarrass his grandmother, the Queen, but, "We'll make sure that we dig him in the ribs a bit and embarrass him—make him lose a bit of hair."
Lady Louise Windsor, Bridesmaid
This 7-year-old is Prince William's first cousin and the daughter of Prince Edward, Earl of Wessex (Prince Charles' brother) and his wife Sophie, Countess of Essex. While not officially titled a princess, the little girl is ninth in line to the throne.
The Hon. Margarita Armstrong-Jones, Bridesmaid
The 8-year-old is Prince William's second cousin and daughter of Viscount and Viscountess Linley. Her late grandmother, Princess Margaret, was the Queen's younger sister. Still following as we play royal catch up? Good. Margarita's aunt, Sarah Armstrong-Jones (now Lady Chatto), was a bridesmaid to Princess Diana and helped maneuver her 25-foot train through the cathedral.
Grace van Cutsem, Bridesmaid
Grace's dad Hugh van Cutsem is Prince Charles' godson, and her uncle Edward served as a pageboy at Prince Charles and Lady Diana's 1981 wedding. And the family friendship doesn't stop there: Prince William is a godfather to his three-year-old bridesmaid.
Eliza Lopes, Bridesmaid
Three-year-old Eliza is the granddaughter of Prince William's step-mother, Camilla Parker Bowles (now the Duchess of Cornwall). Kate and William also attended the wedding of Eliza's parents, Laura and Harry Lopes, back in 2005. And so the circle is complete.
William Lowther-Pinkerton, Page Boy
The 10-year-old's father, Jamie Lowther-Pinkerton, was a former aide to the Queen Mother and is now part-time Private Secretary to Princes William and Harry. He once ran a Special Forces counter-narcotics operations in Colombia for the British Army and now has the (only slightly) more leisurely responsibility of planning the royal wedding.
Tom Pettifer, Page Boy
Eight-year-old Tom is another of Prince William's godchildren and the son of William's former nanny, Tiggy Legge Bourke (now Tiggy Pettifer). Not only did she look after William and Harry when they were young, but she's credited with comforting them through the death of their mother, Princess Diana.