In a parallel universe visited by the Third Doctor, the Conclave was a super cabinet designed to ensure world peace which was composed of the leaders of Earth's five continents.
The leader of the Republic of Great Britain represented Europe, the President of the American Confederation represented the Americas while White Russia, the Asian Co-Prosperity Sphere and India each had their own representatives.
It was analogous to the United Nations Security Council in N-Space. (PROSE: The Face of the Enemy)