Royals discuss Queen in 90th birthday documentary
The Prince of Wales and the Duke and Duchess of Cambridge will be among the royals paying tribute to the Queen in a TV documentary for her 90th birthday.
ITV said the film would screen in the spring, and also announced plans for The Queen's 90th Birthday Celebration - a live event hosted by Ant and Dec.
The event in Windsor Castle's grounds will feature some 900 horses.
The BBC also announced its plans, including a "landmark documentary" and three days of live events in June.
The ITV documentary has the working title The Queen At Ninety, and marks the Duchess of Cambridge's first solo television interview.
Nick Kent, an executive producer on the two-hour programme, said: "We've been fortunate to have the participation of so many members of the Royal Family to mark this historic milestone in the life of the Queen.
"It's a remarkable story of an extraordinary life which in so many ways reflects the changing face of the nation."
The Queen's 90th will be marked with a weekend of national celebrations around the time of her official birthday in June, following events earlier in the year to mark the day she was born - 21 April 1926.
BBC One's coverage of three days of live events starts on Friday 10 June with a service of thanksgiving at St Paul's Cathedral.
That will be followed on the Saturday by the Trooping the Colour ceremony, with the weekend celebrations coming to a close on Sunday with the Patron's Lunch on The Mall, where 10,000 people will gather to celebrate the Queen's patronage of more than 600 charities and organisations.
The corporation also promises a BBC One documentary, documentaries on Radio 2 and the World Service, and coverage on BBC News outlets around the country.
"The BBC is offering an unrivalled range and breadth of programmes to mark Her Majesty 90th birthday," said Charlotte Moore, controller of TV Channels and iPlayer.
"This is a significant moment for the nation and the BBC will be right at the heart of the celebrations."
In May, ITV will broadcast live The Queen's 90th Birthday Celebration, which will tell her life story from her birth in 1926 through her coronation in 1953 and her reign spanning more than 60 years.
Hosts Ant and Dec said they were "honoured".
The presenting duo added: "This spectacular evening will bring together some of the best-known names in the entertainment world."
Hosted by the Royal Windsor Horse Show, the event will feature hundreds of participants from around the world, including The Oman Royal Cavalry, The New Zealand Army Band, The Royal Canadian Mounted Police, Azerbaijan Cossack Riders, South Australian Police Band and The Fijian Army Dancers and Band.
The King's Troop Royal Horse Artillery, 100 Military and Commonwealth Pipers and The Household Cavalry Mounted Regiment will also perform.
It was announced in May that plans for the Queen's 90th birthday would celebrate her "love" of horses and "deep involvement" with the armed forces.
It will also celebrate her "dedication to the Commonwealth".
It was announced that performers will include singers - including Katherine Jenkins - musicians and dancers as well as actors, actresses and artists.
Event producer Simon Brooks-Ward, who was responsible for the Diamond Jubilee Pageant in Windsor, said there would be "a very happy and celebratory feel" to the event.
Ant and Dec recently followed Prince Charles around for an ITV documentary celebrating the 40th anniversary of his charity The Princes Trust.
They also interviewed Princes William and Harry for that documentary.