PLATES 100, 194, 211 and 221 are reproduced by gracious permission of Her Majesty the Queen.
Plate VII is reproduced by gracious permission of His Serene Highness the Prince of Liechtenstein.
We wish to express our sincere gratitude to the following private owners and museum authorities for permission to reproduce paintings in their collections and for supplying photographs:
The late Mr. D. G. van Beuningen, Vierhouten; Captain E. G. Spencer Churchill, Northwick Park; His Excellency Baron van der Elst, Rome; Mr. Robert Lehman, New York; Mme von Pannwitz; the Earl of Pembroke, Wilton House; the Earl of Radnor, Longford Castle; the Earl of Verulam, Gorhambury; Mrs. Weld Blundell, Liverpool.
Rijksmuseum, Amsterdam; Musée Royal, Antwerp; Kaiser Friedrich Museum, Berlin; Museum of Fine Arts, Boston; College van Kerkvoogden, Breda, Memlinc Museum, St. John's Hospital, Bruges; Herzog Anton Ulrich Museum, Brunswick; Fitzwilliam Museum, Cambridge; Museum, Cassel; Devonshire Collection, Chatsworth, Art Institute, Chicago; Museum of Art, Cleveland; Wallraf-Richartz Museum, Cologne; Institute of Arts, Detroit; Rijksmuseum Twenthe, Enschede; Staedel Institute, Frankfurt; Frans Hals Museum, Haarlem; Lakenhal, Leyden; Walker Art Gallery, Liverpool; National Gallery, London; Castle Rohoncz Collection, Lugano-Castagnola; Prado, Madrid; Alte Pinakothek, Munich; Metropolitan Museum, New York; Frick Collection, New York; Museum, Oldenburg, John G. Johnson Art Collection, Philadelphia; Museum Boymans, Rotterdam; Centraal Museum, Utrecht; Kunsthistorisches Museum, Vienna; National Gallery of Art, Washington; Art Museum, Worcester, Mass.; and Martin von Wagner Museum, Würzburg.
Further photographs have been supplied by A.C.L., Brussels; De Spaarnestad, Haarlem; Alinari, Florence; Archives Photographiques, Paris; Bulloz, Paris; Giraudon, Paris; and Anderson, Rome.