This is the first general biography of Charles de Bourbon, Constable of France (1490-1527), to appear for some time. The events of Bourbon’s life form a dramatic and compelling story, centering on his treasonable plot to dismember France in 1523; his victory at Pavia and capture of Francois I in 1525; and his command of the imperial troops who sacked Rome in 1527 The narrative, illuminated by the findings of modern scholarship, is integrated into the broader context of French and international history. The biographical idiom is used to examine the evolution of French social and political institutions in the first decades of the sixteenth century, the strains induced in the French and Hapsburg monarchies by the long struggle for primacy in Italy, and the rapid transformation of war and diplomacy in the period.