Amid the disintegration of the Kingdom of Italy in the eleventh and twelfth centuries, a new form of collective government--the commune--arose in the cities of northern and central Italy. Sleepwalking into a New World takes a bold new look at how these autonomous city-states came about, and fundamentally alters our understanding of one of the most important political and cultural innovations of the medieval world.

Chris Wickham provides richly textured portraits of three cities--Milan, Pisa, and Rome--and sets them against a vibrant backcloth of other towns. He argues that, in...