An early interest in socialism led to his expulsion from Berlin in 1846 but, after the outbreak of the Revolutions of 1848, he returned to Germany to help set up a republic in Baden. Forced to flee, he went to England, where he spent 13 years in close association with Karl Marx. He returned to Germany in 1861 and in 1863 founded the League of German Workers’ clubs with August Bebel. A pacifist, he refused to vote for war credits for the war with France in 1870, was convicted of treason, and spent two years in prison. In 1874 he returned to the Reichstag and in 1875, with the followers of the late Ferdinand Lassalle (1825–64), helped to form the German Social Democratic Labour Party, which became the German Social Democratic Party (SPD) in 1891.