The first room he finished for Julius II. was so rich in effect and beautiful in colour that the Pope could scarcely wait for more rooms as fine. Raphael had to call in a large number of assistants to enable him to cover the walls fast enough to please the Pope, and the quality of the work began to deteriorate. The uneven merit of his frescoes foretold the consequence of overwork despite his matchless facility and power. But in his panel pictures, when he was not hurried, his work continued to improve until he reached his crowning achievement in the Sistine Madonna painted three years before his death.
Raphael was thirty-seven when he died in 1520, and very far from coming to the end of his powers of learning. Each picture that he painted revealed to him new difficulties to conquer, and new experiments to try, in his art. We seem compelled to think that had he lived and laboured for another score of years, the history of painting in Italy might have been different. In Rome and Florence no successor attempted to improve upon his work. His pupils and assistants were more numerous than those of any other painter, but when they had obtained some of his facility of drawing and painting they were contented. None of them had Raphael’s genius, yet all wished to paint like him; so that for the following fifty years Rome and Florence and Southern Italy were flooded with inferior Raphaelesque paintings, which tended to become more slip-shod in execution as time went on, and more devoid of any personal note. It was just as though his imitators had learnt to write beautifully and then had had little to say.