The purpose of this study of Azariah de'Rossi's Me~or Enayim is primarily to establish the precise scholarly context of de'Rossi's historical investigations by means of an analysis of the author's use of sources. The first section is devoted, for the most part, to de'Rossi's study of the origins of the Septuagint and to his use and evaluation of the work of Philo and Josephus. In relation to his Septuagint studies it is argued that his work bears greater affinity to northern European than to Italian antiquarian scholarship of his time. The original nature of de'Rossi's critique of Philo is demonstrated and is considered in the light of Christian attitudes towards the Hellenistic Jew. As regards de'Rossi's Jewish sources attention is given to his controversial analysis of the Aggadoth and to his evaluation of some post-Talmudic sources. Further clarification as to the scholarly framework of de'Rossi's researches is provided in the chapter on his use of the work of two Christian writers - Augustinus Steuchus and Annius of Viterbo. A re-appraisal of the Jewish reaction to the publication of the Me'or (Enayim is given in the Postscript. In the second par~ an annotated English translation of five ~ c chapters of the Me'or _Enayim have been provided as illustration of the discussions of the first part of the thesis.