Prince William and Kate Middleton have married at Westminster Abbey, appearing afterwards on the balcony of Buckingham Palace where they sealed their union with two kisses before a cheering crowd.
They were watched and cheered by thousands of well wishers who gathered outside the palace, as an RAF fly-past took place.
Some 1900 guests were invited to the wedding ceremony, with many millions watching the televised service.
The couple will now be known as the Duke and Duchess of Cambridge.
The Queen hosted a buffet reception for 650 guests at Buckingham Palace, the BBC reports.
About 300 close friends and relatives stayed on for a formal black tie dinner and disco in the evening hosted by Prince Charles.
Kate Middleton wore an ivory and lace gown designed by Sarah Burton at Alexander McQueen and a Halo tiara belonging to Queen Elizabeth, made by Cartier.
Prince William wore the dress uniform of Colonel of the Irish Guards, his most senior honorary appointment.
The church service ran smoothly, although the Prince struggled to place the wedding ring on his bride's finger.
The couple signed the marriage register after saying their vows, in which there was no promise to obey.
It is the biggest royal occasion in Britain since the marriage of William's parents, Prince Charles and Diana, in 1981.
Celebrities who attended the ceremony included singer-songwriter Sir Elton John and his partner David Furnish, former England football captain David Beckham and his wife Victoria and actor Rowan Atkinson.
Police estimate that 1 million people lined the route between the church and Buckingham Palace and 500,000 watched the couple appear on the palace balcony after the service.
Security was tight with more than 5000 officers on duty - more than 900 of them along the wedding route. Most were in uniform, but some plain clothes officers mixed with the crowd.
The global TV audience was expected to have been 2 billion.
William drives bride in Aston Martin
After their wedding reception at Buckingham Palace, Prince William drove his new bride to Clarence House in a classic blue Aston Martin.
The vintage convertible, which belongs to Prince Charles, was decorated with balloons and red, white and blue ribbons and bore a number plate reading 'JU5T WED'.
The couple were followed by some of the prince's RAF colleagues in a Sea King helicopter.
Title bestowed by Queen
The couple have become the Duke and Duchess of Cambridge on their marriage.
All titles are in the gift of the Queen and it was up to the monarch to choose which to give her grandson and his new wife.
It is tradition that royal men receive a title on their wedding day and a dukedom is the highest rank in British peerage.
As well as a duchess, Catherine will also technically become Princess William of Wales.
According to protocol, she is not officially Princess Catherine, as she was not born a princess in her own right.