Jean-Paul Marat's role in the French Revolution has long been a matter of controversy among historians. Often he is portrayed as a violent, sociopathic demagogue. This biography challenges that interpretation and argues that without Marat's contributions as an agitator, tactician, and strategist, the pivotal social transformation that the revolution accomplished would not have occurred.

Clifford D. Conner argues that what was unique about Marat - setting him apart from all other major figures of the revolution, including Danton and Robespierre - was his total identification with the struggle of the propertyless classes for social equality. Fresh ideas surrounding the Champs de Mars Massacre, his assassination, the cult of Marat and the Legende Noire are all explored.