Assistance has been supplied by numerous works. The largest debt is due to the learned art historian Ferdinand Luthmer, whose standard work _Gold und Silber_ has afforded most important aid. From Rücklin's _Schmuckbuch_ I have constantly derived instruction; and Fontenay's _Bijoux anciens et modernes_ has been a storehouse of information. Other books which have been of service are included in the Bibliography. It is now my duty and pleasure to express my obligations to all those whose unvarying kindness has facilitated my researches. Special thanks are due: to Lady Rothschild, who has presented me with photographs, specially taken for the purpose, of some of her choicest jewels; to Lady Fuller-Eliott-Drake, who at considerable personal inconvenience brought the Drake jewels to London; to Mr. Jeffery Whitehead, who despatched for my use a number of jewels from his collection; to Mr. Max Rosenheim, who, besides placing at my disposal his unrivalled series of engraved designs for jewellery, has read through and corrected the portion of the subject dealing with engraved ornament; to Sir John Evans, K.C.B., who has guided me personally through his splendid collections of early jewellery; and to Dr. Williamson, for assisting me in many ways, and for the loan, on behalf of Mr. J. Pierpont Morgan, of copyright photographs of the finest enamelled miniature-cases from his catalogue of Mr. Morgan's collection, with leave to describe and reproduce such of them as I might select for this volume. Among those who have favoured me with permission to publish the treasures in their possession I must gratefully mention Lady Cook (Viscondessa de Monserrate), Lady Ramsay, Lady Monckton, Mrs. Holman Hunt, Mrs. Percy Macquoid, the Marquess of Clanricarde, Viscount Falkland, and Lord Fitzhardinge; also Herr James Simon, of Berlin, and Lieut.-Col. G. B. Croft Lyons, who have presented me with photographs of their jewels. Thanks are also due to Dr. Kitchin, Dean of Durham, for the photograph of St. Cuthbert's Cross; to Dr. Spooner, Warden of New College, for permission and aid in photographing the New College jewels; to Dr. J. Anderson, Director of the National Museum of Antiquities of Scotland, for the loan of blocks of two jewels in the Edinburgh Museum; to Mr. F. G. Hilton Price, who enabled me to photograph the old ledgers in Child's Bank; and to Mr. J. T. Herbert Baily, for leave to reproduce illustrations to my articles on the King's gems and jewels at Windsor Castle in the "Connoisseur" (1902-3). The names of many others, who have kindly lent me jewels or photographs, will be found, attached to the individual objects, in the List of Illustrations.