In a time of grave uncertainty about the future of our planet, the radical potential of democracy is more important than ever.

From its beginnings in Syria-Mesopotamia - and not Athens - to its role in fomenting revolutionary fervour in France and America, democracy has subverted fixed ways of deciding who should enjoy power and privilege, and why. For democracy encourages people to do something radical- to come together as equals, to determine their own lives and futures.

In this vigorous, illuminating history, acclaimed political thinker John Keane traces its byzantine history, from the age of assembly democracy in Athens, to European-inspired electoral democracy and the birth of representative government, to our age of monitory democracy. He gives new reasons why democracy is a precious global ideal, and shows that as the world has come to be shaped by democracy, it has grown more worldly - American-style liberal democracy is giving way to regional varieties with a local character in places such as Taiwan, India, Senegal and South Africa.

In an age of cascading crises, we need the radical potential of democracy more than ever. Does it have a future, or will the demagogues and despots win? We are about to find out.