Hellmut Ritter (27 February 1892 – 19 May 1971) was a leading German Orientalist specializing in Arabic, Persian, and Turkish, and an authority on Sufi ritual and mystical beliefs.
In Istanbul Ritter realised the city's ancient libraries held a wealth of manuscripts and literary treasures that lay moldering and unregarded.
Then a new and local opportunity arose, due to Mustafa Kemal Atatürk's rapid modernisation of Istanbul and Turkey.
After the defeat of the Nazis in World War II Ritter was able to return to Germany in 1949, and this enabled the completion of his most important work: the encyclopaedic manual on the rituals and beliefs of Islamic mysticism Das Meer der Seele (1955 in German).
Upon his return to Turkey Ritter began work at the Istanbul University on a UNESCO-funded project to catalogue the scattered ancient poetry manuscripts in the various city archives.
By 1960 Ritter's early sympathies with the mystical orders of Islam and his and assiduous gathering of their MS texts ensured their survival.