The Purpose of this study is to understand the development of German sports by studying of Carl Diem`s life and thought, who is called a forerunner of modern German sports. This study covers his life, personality, thought and achievements contributing to world sports history as well as to Germany. People who are believed to have influenced on shaping Carl Dime`s life and thought are not like "Jahn" or "Guts Muths" who were sports professionals. How was it possible that Carl Diem was under the influences of the people outside of sports field? Carl Diem was not educated in a stubborn and directive way like in Turnen. So he is believed to have had liberal ideas and to have taken flexible stance as a journalist, sports organizer, manager, and a person enlightening in the incessant change of the time. Accordingly, he was able to protest against Nazi and is living in the heart of world sportmen as well as of the German as a figure who led unifying and restoration of postwar German sports, youth education, and the national unity.