William Kent (1685-1748) was great without a hint of gravitas, a con man who became one of the artistic geniuses of his age. He was a high camp Yorkshire bachelor, brought back by Lord Burlington from an artistic apprenticeship in Rome where he had painted for a cardinal and won prizes from a pope. In London he charmed the surly old Hanoverian King George I, redecorated Kensington Palace for him with a clumsy bravura, and survived the subsequent...