A giant street party for the Queen's 90th birthday will celebrate her support of more than 600 organisations and charities, organisers say.
The Patron's Lunch will be attended by 10,000 guests - many from charities supported by the Queen - in London's The Mall, on Sunday 12 June next year.
The Duke of Edinburgh, Prince William and Prince Harry will attend the party.
Organiser Peter Phillips - the Queen's grandson - said his grandmother was "excited" at the prospect of the event.
The street party will be the culmination of a weekend of national events next summer to celebrate the Queen's official 90th birthday.
A service of thanksgiving - which will be attended by the Queen and Prince Philip - will be held at St Paul's Cathedral on Friday 10 June.
The following day the traditional Trooping the Colour ceremony will be staged in Horse Guards Parade.
Celebrations are also being held in May next year, including four events inside the grounds of Windsor Castle.
The Mall will be lined with picnic tables for the street party, during which guests will enjoy a hamper-style lunch, organisers say.
Of the 10,000 tickets, most will be allocated to guests from the Queen's charities and organisations, but some will be made available for public ballot.
Members of the public will also be able to share in the festivities at live sites situated in Green Park and St James's Park.
The street party will raise money for the new Patron's Fund, which will be used to support specific initiatives and projects run by the Queen's charities.
Mr Phillips, who is helping to organise the street party in his role as director of events agency Sports Entertainment Ltd, said the celebration would emphasise the Queen's support for her charities.
"We want to reflect the service she's given to all her organisations and charities," he said.
Speaking of his grandmother, he added: "She's obviously been kept abreast through her office about all the developments, and the times I've had the chance to talk to her she's been excited by it."
The Queen is patron of a wide range of organisations, including children's charity Barnardo's, Battersea Dogs and Cats Home, and Great Ormond Street Hospital.
The Patron's Organisations is a collection of 626 charities and organisations that span 16 different sectors and are represented across the UK and the Commonwealth.
BBC News
