Maximilien Robespierre was a prominent leader of the French Revolution known for his radical ideas and his role in the Reign of Terror. He was a member of the Committee of Public Safety and advocated for revolutionary ideals such as liberty, equality, and fraternity. His policies included the use of guillotines to eliminate perceived enemies of the revolution, which resulted in thousands of executions. Robespierre believed that terror was necessary to maintain the revolution's goals, but his excesses ultimately led to his downfall in 1794 when he was arrested and executed, marking the end of the radical phase of the revolution.