During 1907 Wallace travelled to the Congo Free State to report on atrocities committed against the Congolese under King Leopold II of Belgium and the Belgian rubber companies. Isabel Thorne of the Weekly Tale-Teller penny magazine, invited Wallace to serialise stories inspired by his experiences there. These were published as his first collection Sanders of the River , became a best seller and was adapted into a film starring Paul Robeson in 1935. Wallace went on to publish eleven more collections. These are tales of exotic adventure and local tribal rites, set on an African river.