Rohwer wrote over 400 books and essays on World War II naval history and military intelligence, which gained him worldwide recognition as a prominent historian and a leading authority on U-boats.
[2] During that time he got into contact with Günter Hessler – son in law to Karl Dönitz – and was commissioned by the British Royal Navy to write an official account of the U-boat war 1939–1945.
In the 1970s, Rohwer researched the history of cryptanalysis in World War II and especially the decoding of Enigma by the British and Polish scientists.
[3][4] In a cooperation of the Bibliothek für Zeitgeschichte and the University of Stuttgart, the congress "Der Mord an den europäischen Juden" (The murder of the European Jews) took place in May 1984.
Together with Eberhard Jäckel, Rohwer edited the book "Der Mord an den Juden im Zweiten Weltkrieg.