Jean-Paul Marat was a physician and political thinker who rose to prominence during the French Revolution, notably during the Reign of Terror. He was a fervent follower of the revolution's ideas and an outspoken advocate for the rights of the lower classes. Marat used his journal to espouse his radical viewpoints and to urge direct action against suspected adversaries of the revolution. He was a key figure in the planning of the September Massacres of 1792, in which crowds murdered imprisoned counter-revolutionaries.