Reynolds rarely made preliminary sketches even for complex compositions. But the magnificent group of the family of the Duke of Marlborough, which still dominates the Red Drawing Room at Blenheim Palace, was clearly an exception. Conceived in the grandest traditions of Rubens and Van Dyck, it was to influence society portraiture into this century. This sketch shows the painter struggling with the problem of integrating the solemn splendour of the adults with a more modern, relaxed informality preferred for young children and dogs. The end result shows brilliantly the range of Reynolds's wit and originality as a portraitist.