 Before going up to Cambridge in 1958 he completed his national service as an airframe mechanic in the Royal Air Force stationed at RAF Geilenkirchen on the German-Dutch border near Aachen.At Cambridge Röhl achieved a First on both Parts of the Historical Tripos and in 1961 went on to work for a PhD under the supervision of Professor Sir Harry Hinsley.He spent the academic year 1962–63 in the archives of West and East Germany researching the history of Imperial Germany in the aftermath of Bismarck's fall from power in 1890.