The present book is based on a Ph. D. thesis originally suggested by the late Sir Lewis Namier. I was privileged to have his guidance, especially during the initial and most difficult stages of the research, and it is largely due to his sound advice that I was able to find my way in the maze of archival material.
I am deeply indebted to Professor J. L. Talmon, my teacher and tutor at the Hebrew University of Jerusalem, for his constant encouragement and invaluable help and advice.
I should also like to extend sincere thanks to Dame Lucy S. Sutherland and to Professor A. H. John of the London School of Economics for their guidance and advice; to Dr Richard D. Barnett of the Jewish Historical Society of England for his continuous interest and help; to Dr H. E. S. Fisher for numerous references to Jewish merchants in documents relating to the Portugal trade; and also to the Directors and staff of the Public Record Office, the British Library, the India Office Library, the Bank of England, Hoare's Bank, the firm of Mocatta and Goldsmid, and the Central Archives for the History of the Jewish People in Jerusalem.
Special thanks are due to my friend Edgar R. Samuel for his unfailing assistance, encouragement, and catching enthusiasm.
I am much indebted to the British Council and to the Friends of the Hebrew University in England whose generous grants made this research possible, to the Jewish Historical Society of England for its help towards the publication of this book, and to the Marc Fitch Fund for a grant towards editorial expenses in its preparation.
Profoundest thanks are due to Dr Aubrey Newman of Leicester University, who edited this book for publication, for his selfless and invaluable help. He devoted much of his precious time to the task and successfully accomplished that most difficult of assignments — the turning of a Ph. D. thesis into a book. Although his name does not appear on the title page, he has a very prominent share in this book.