Louis-Auguste Blanqui was a French socialist revolutionary and philosopher. A pivotal figure of the 19th-century French radical left, he was a staunch advocate for communism and a proponent of the revolutionary theory that came to be known as Blanquism. His political career was marked by a relentless opposition to all forms of monarchy and capitalism, leading to his repeated imprisonment by every French regime of his lifetime. He spent 33 of his 75 years in prison, earning him the nickname L'Enfermé.