This book is an examination of the nature of the governments of towns and cities, great and small, in Renaissance Italy, and of why oligarchic regimes were becoming increasingly prevalent. Themes and questions arising from a case-study of the dramatic changes in the government of fifteenth-century Siena form the basis for the analysis of popular government and oligarchy throughout Italy, from Piedmont and the Veneto to Sicily, and of how they were shaped by social change, institutional developments and external threats and pressures, especially war. In a field dominated by local studies, this comparative approach provides a fresh understanding of the important problem of how and why broadly-based governments were losing ground to oligarchy throughout Italy.