Carolyn Hayman, chief executive of young people's charity the Foyer Federation, is leaving to join a new conflict resolution charity.
She will become executive director of Peace Direct, which was formed in September 2002 with the aim of finding alternatives to war and helping people in war-torn areas to use non-violent methods to ease conflict locally.
The charity will also attempt to influence government policy and work with other conflict resolution charities.
Peace Direct will concentrate on raising solidarity between people in the UK and those working in conflict areas. But its main purpose will not be to campaign.
Chair Anita Roddick said: "Peace Direct offers an anti-war action plan.
This is the civil-rights movement of the 21st century."