This volume differs from previous members of the series, which covered either a single artist, a family of artists or a whole school, in that it deals with the drawings of two artists who are not very obviously connected. The reasons for including Castiglione and Stefano della Bella between the same covers are primarily those of practical convenience, in that their combined works compose a volume of about the right size, and that neither of them fits in with any major group or school as represented in the Royal Library. It would, however, be possible to find historical justifications for making them bedfellows. They were near to being contemporaries; both were primarily draughtsmen rather than painters; both stand at the crossing of the currents northern and Italian art. But such arguments would be special pleading; and it cannot be denied that as artists they are of very different types Castiglione starts as a naturalist in the Flemish manner and turns towards the baroque religious style; Stefano starts as a retardataire Mannerist in the style of Callot and later comes under the influence of Dutch art.
Some explanation must also be given of the disparity in the treatment which the two artists here receive. The introduction to the section dealing with Stefano della Bella is no more than an essay, whereas that for Castiglione has in course of time become almost a short monograph. This difference in scale was dictated by the nature of the material, and by the existing literature in the two cases. In the case of Stefano della Bella the ground has already been fairly well worked, though more in relation to the etchings than to the drawings. Moreover, the drawings by him in the Royal Library, though numerous and fine in quality, form only one of many groups which survive to this day, those in the Uffizi, the Louvre, and the Hermitage being at least of nearly equal importance. This catalogue did not, therefore, seem the appropriate occasion for a full survey of his work.
The case of Castiglione is quite different. The only monograph on him deals almost exclusively with his paintings and leaves much to be desired, even in this field. Moreover, since its publication many paintings have been discovered, mainly in English private collections. Finally, the drawings at Windsor form by far the most important body of evidence available about his work and development. I have therefore thought it worth while to attempt a survey on a wide scale, correcting errors in previous biographies, proposing a chronology both of drawings and paintings as, far as I could gain access to them, and trying to place the artist in the general perspective of Italian and, in certain respects, of European art. This task was perhaps over-ambitious, and I am only too well aware of the gaps that I have left. But to fill them would have required lengthy research, which it was impossible to undertake at the moment, and visits to places which are no longer accessible. My principal hope is that the results here presented may encourage others to correct and amplify them.
The debts I have incurred in preparing this volume are many. To Sir Owen Morshead, the Royal Librarian, I owe a debt which only those who have taken part in the work on this series can properly appreciate. Professor Johannes Wilde has helped me throughout the preparation of the catalogue, from the moment before the end of the war, when he went through my first tentative classification of the Castiglione drawings, to the last stage, when he read the manuscript of the introduction. Over the work on Stefano della Bella I am particularly indebted to Miss Erica O'Donnell, who took up . . .