This book accompanies an exhibition at Waddesdon Manor, Buckinghamshire, on one of the great Italian painters of the seventeenth century, Giovanni Francesco Barbieri, known as Guercino (1591-1666). It brings together for the first time Waddesdon's King David with three paintings of sibyls (female prophets from classical antiquity) on loan from the National Gallery in London and the Royal Collection. Readers and visitors will be immersed in the poetry, colour and majesty of these works, which were all painted in the year 1651. The book investigates the relationship between David, the Jewish patriarch, psalmist and prophet who foretold the coming of the Messiah and whom Christians believed prefigured Christ, and the pagan seers, who supposedly prophesied Christ's birth. With their brilliant portrayal of flesh and ermine, paper, wood and stone, these works conjure up ideas about vision and inspiration, poetry and prophecy. The exhibition also introduces Guercino's early masterpiece Moses (c. 1618-19), recently rediscovered and acquired for Waddesdon.