Mountaineers past and present will gather in London later on the 60th anniversary of Sir Edmund Hillary's historic ascent of Mount Everest.
Former and current mountaineers will join the sons of the first men to reach the summit at the signing of a newly-released book on the expedition.
The occasion marks 60 years since Sir Edmund and Tenzing Norgay became the first men to reach the 29,028ft (8,848 metres) summit on May 29 1953.
Later, the Queen and the Duke of Edinburgh will attend a reception to mark the anniversary at the Royal Geographical Society, where they will watch footage from the historic achievement, view an exhibition, and meet families and guests.
In a separate occasion, the 60th anniversary will also be marked with the signing of a new book on the expedition, attended by key figures from the mountaineering world.
Hillary and Norgay's sons, Peter Hillary and Jamling Tenzing Norgay, will be joined by celebrated mountaineers Sir Chris Bonington, Stephen Venables and Doug Scott, who have all contributed personal reflections to the newly-released The Conquest Of Everest - Original Photographs From The Legendary First Ascent.
The book features a previously-unpublished collection of photographs from the historic climb, put together by the late George Lowe, a member of Hillary's team, with help from family friend and historian Huw Lewis-Jones.
Mr Lowe was the last surviving member of the team until he died earlier this year aged 89. Born in Hastings, New Zealand, he met Sir Edmund while climbing in the Southern Alps on his holidays.
The pair became friends and in 1951 were members of the first New Zealand expedition to the Himalayas. They went on to join the British Everest expedition led by British Army colonel John Hunt and to conquer the mountain in 1953, days before the coronation of Queen Elizabeth II.
Over the past few years, up until his death, Mr Lowe and his family worked with Dr Lewis-Jones to put together his memoirs and photographs from the climb so they could be published this year. The book of previously-unpublished photographs includes landscapes, candid portraits and action shots portraying the day-to-day moments of the expedition.