More than 8,000 clansmen and clanswomen from around the globe will come together in Edinburgh for The Gathering in the Holyrood Park in July 2009.
It will be the first time since Sir Walter Scott's Royal Pageant in 1822 that so many clans have assembled in the city.
The event will be held as part of the Homecoming Scotland celebrations.
The programme will feature the 2009 World Highland Games Heavy Events Championship and an International Gathering of Scottish Clans and Families.
A parade of the clans up the Royal Mile will culminate in a spectacular pageant on the esplanade of Edinburgh Castle.
There will also be a strong focus on traditional Highland Games, with solo piping and Highland dancing competitions, and there will be opportunities for people to research clan histories and genealogy.