Hanoverian diplomat, professor of jurisprudence at the University of Göttingen from 1783, the original editor of what remains the largest collection of treaties in the world. He singlehandedly edited Recueil des traités, covering treaties from 1761, through the first seven volumes (1791–1801) and collaborated with his nephew Karl von Martens in editing four additional volumes (1802–08). The Martenses and numerous later scholars prepared Nouveau recueil général des traités, dealing with treaties from 1808 (112 vol., 1817–1944).