ONE of the most important acquisitions of an illuminated manuscript during Derek Turner's years in the Department of Manuscripts was the Psalter from the collection of the Duke of Rutland at Belvoir Castle, acquired in 1983, and now Add. MS. 62925. For a long time the manuscript had been of very restricted access, and was known to most scholars only through the facsimile edition prepared by Eric Millar for the Roxburghe Club in 1937. The availability of the Psalter for study in the British Library has at last enabled a detailed and prolonged examination of the book to be carried out. The black and white plates in the facsimile edition, although of excellent quality, had not made it possible to assess the number of artists involved and to describe the ways in which they divided their labour. As is often the case, the difference in use of colour clearly indicates the work of an individual artist when other aspects of the style may not, on first appearance, seem too different from the work of another hand.