On 1 February 1845, Karl Marx signed a contract with the publisher Carl Leske for his first major work on political economy, a two-volume work entitled Kritik der Politik und Nationalökonomie, to be based largely on the manuscripts he had written in Paris in 1844. Signed in Paris, where Marx was living at the time in 38 Rue Vanneau, the contract provided Marx with a 1,500-franc advance on the 3,000-franc fee to be paid in full upon completion of the two volumes. Two years later Leske cancelled the contract with Marx, who never finished the work. The photograph here shows the verso of Marx’s copy of the contract, which is held in the archives of the International Institute of Social History in Amsterdam.