Street parties on big royal occasions are a long-standing British tradition, from Prince Charles and Princess Diana's wedding in 1981 to Queen Elizabeth II's golden jubilee in 2002.
There were 5,500 applications for street closures across the country, with residents taking over roads with long tables, baked treats, picnic meals, brass bands and festive buntings.
Many towns and cities erected outdoor screens so people could watch the wedding ceremony of Prince William and Kate Middleton in Westminster Abbey - and their kiss from a Buckingham Palace balcony a little later.
About 100 charity workers and local children were invited to a party in Downing Street, home to Prime Minister David Cameron and his family. They were served egg sandwiches, cupcakes, fizzy drinks and tea poured from stainless steel teapots into white china cups.
In London's Hyde Park, tens of thousands of people watched the ceremony on giant screens, many adorned with union jacks, bridal gowns, face masks, wigs and home-designed hats.