It is my pleasure to express my sincere gratitude to my first supervisor. Dr. Michael V. McDonald, for his invaluable guidance and kind assistance during the research and the preparation of this thesis. I am indebted to my second supervisor Dr. C. Hillenbrand for supervision that has been most beneficial to the revision of this study. I am most grateful to my former supervisor Prof. Dr. Nejat Göyünç, who is working as an experienced supervisor at the Archive Department in the Univesity of Istanbul and who read my origina text through and made valuable suggestions.