Video: William marries his princess as billions watch live
They had the eyes of the world upon them and Prince William, now the Duke of Cambridge, said all he had to do was get his lines right.
He did, and so did his new wife, as they both delivered a flawless performance during the wedding ceremony.
There were 1,900 guests in Westminster Abbey, hundreds of thousands of well-wishers lining the streets of London, and as many as two billion people watching around the world.
And the couple got their marriage off to a perfect start, both beaming with pleasure.
On an impromptu walkabout last night William, told well-wishers "All I've got to do is get the lines right."
He need not have worried.
Both he and Kate, now the Duchess of Cambridge, spoke confidently as the Archbishop of Canterbury, Dr Rowan Williams, solemnised their marriage.
Before the ceremony William and Prince Harry had the demeanour of any other groom and best man.
Both checked their hair, patting it down after removing their hats as they entered the abbey.
William chatted with guests, smiling and looking relaxed, while Harry appeared the more nervous of the two.
The bride-to-be arrived at Westminster Abbey exactly at 11am.
She was all smiles as she walked up the aisle accompanied by her father, Michael.
As she approached the front of the church, Harry looked back, cracked a broad smile and said a few words to his brother.
William faced forward until Kate arrived.
The couple looked lovingly at each other as they exchanged a few words, William looking down to admire the length of Kate's dramatic dress.
The Archbishop asked William: "Wilt thou love her, comfort her, honour and keep her, in sickness and in health; and, forsaking all other, keep thee only unto her, so long as ye both shall live?"
William's voice crackled slightly as he said: "I will."
As Kate said "I will" to the same vows there was a loud cheer from the crowd outside.
Like Diana, Princess of Wales, Kate did not promise to obey her husband.
William spoke steadily and confidently as he repeated the words after the Archbishop, saying: "I, William Arthur Philip Louis, take thee, Catherine Elizabeth to my wedded wife, to have and to hold from this day forward, for better, for worse: for richer, for poorer; in sickness and in health; to love and to cherish, till death us do part, according to God's holy law; and thereto I give thee my troth."
Kate took William by his right hand to repeat her vows, which she delivered without fault and which received another cheer from the crowd outside.
There was a nervous moment when William tried to put the ring on the fourth finger of Kate's left hand.
The ring was stuck on the knuckle for a few seconds but then slipped on.
There was more cheering from the crowd outside as the Archbishop pronounced them man and wife.
In 1981 Diana's nerves showed briefly when she called her new husband Philip Charles Arthur George rather than Charles Philip.
The Prince of Wales also slightly muddled his vows referring to "thy goods" rather than "my worldly goods".