Presses Universitaires de France and Fr�meaux & Associ�s offer this biography of Philippe P�tain, analyzed and explained by Jean-Yves Le Naour, a historian specializing in the First World War and the 20th century. Philippe P�tain is a historical subject that goes beyond the character. Jean-Yves Le Naour, a historian specializing in the First World War and the 20th century, presents here not only a biography of Marshal P�tain, but also a history of P�tainism. The historian looks at the myth of P�tain, forged during the First World War as the victor of Verdun, and how the myth took root between the wars, culminating in the revered head of state under Vichy, from 1940 to 1944, when the Marshal posed as the protector of the French while actively collaborating with the occupying forces. The presentation traces an individual trajectory that helps us understand an entire era. Beyond the death of Philippe P�tain, this paper also examines the question of his political memory right up to the present day.