This book breaks new ground by focusing on the great Florentine "super-companies" of the early fourteenth century in their own right. The author closely examines the Peruzzi Company in particular, describing its ownership, family connections, scope of business, organization structure, accounting systems, and its history from 1300 to its dissolution in bankruptcy court in 1347.

From this analysis, the author offers a radical reassessment of the nature and role of these extraordinary organizations. He establishes that although they engaged in all forms of commerce in substantial volume, what made them exceptional was commodity trading, especially in grain, which they conducted on a heroic scale. It was this activity that required heavy capital, sophisticated organization, and an international network.

But the author also exposes the limitations of their financial power and explodes the myth that their downfall was caused mainly by bad loans to Edward III to finance his invasions of France. This book is much more than a business history. It presents the operations of these companies in the context of the swiftly moving political, military, and economic developments in Florence, the Mediterranean, and western Europe during a tumultuous period.