E. P. Thompson was a Marxist, a radical as well as a pacifist, who had been very active, first in the Communist Party of Great Britain, and subsequently in the New Left and in the peace movement. He was one of the founding fathers of European Nuclear Disarmament (END) and widely acknowledged as intellectual leader of the British peace movement, both at home and abroad. In this article, we focus primarily on how his Marxism influenced his commitment to peace. Many of his historical and political writings, including his novels, were extremely popular among peace activists so that one can assume a wide readership and hence considerable influence of Thompson in the peace movement. We shall ask how his Marxism informed his peace activism and wha...