The main sources of Islamic history are the Koran and Hadith. However the books about pre-Islamic Arab history (The period of Jahiliyye), history of Arab literature, history of conquests, biographies etc. take part in the main and auxiliary sources of Islamic history. An Islamic historian who tries to investigate a historical topic has to know his topic’s main and auxiliary sources and their values as a source. This article that we translated into Turkish is an example of this kind of matter