ERINO DEL VAGA was primarily a draughtsman and designer, secondarily a fresco-painter and only very subsidiarily a panel-painter. The key to an appreciation of his style and personality lies in his drawings, which have been even more neglected than his paintings. The number of the former which has been preserved is very considerable and a systematic study of the European collections would, no doubt, reveal a very much larger number than those which are available in reproductions. I have naturally had no opportunity of examining these collections recently and some of the conclusions reached in this article from a first-hand knowledge of English collections only may have to be modified. Nevertheless it seems to me worth while recording some new facts which have come to light on the basis of the material available. In the present article I propose dealing only with the period of Perino's activity in Rome from the death of Raphael in 1520 to his departure for Genoa in 1528.