Prince George has stolen the show as the four generations of the Royal family posed for pictures that will be used on special stamps to mark the Queen's 90th birthday.

George is seen smiling broadly as he stands on a stack of books while holding onto Prince William's hand, with his grandfather and great-grandmother - or as the toddler calls Her Majesty 'gan-gan' -sitting proudly.

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The young future king, who has his blond hair in a side parting and is wearing a smart white Rachel Riley shirt with blue piping, will feature on the first class stamp, as will the other members of the family.

The image of the two-year-old was captured by photographer Ranald Mackechnie as part of a specially commissioned wider portrait of the House of Windsor - the Queen and three future monarchs.

Mackechnie, 55, described the royals as "amazingly relaxed" and said George's joy and energy was fantastic.

Six further stamps have also been released for the special occasion - three focusing on the Queen's family life and three honouring her official role.

They show the Queen: as a young Princess Elizabeth with her father then the Duke of York in around 1930; attending the State Opening of Parliament in 2012; with Princess Anne and Prince Charles in 1952; visiting New Zealand in 1977; with the Duke of Edinburgh in 1957; and riding in an open top carriage with Nelson Mandela in 1996.