Augustus is one of the great what-ifs of the 18th century. He could have turned the accident of ruling two major realms into the basis for a powerful European state - a bulwark against the Russians and a block on Prussian expansion. Alas, there was no opportunity Augustus did not waste and no decision he did not get wrong. By the time of his death Poland was fatally damaged and would subsequently disappear as an independent state until the 20th century.

Tim Blanning's wonderfully entertaining and original new book is a study in failed statecraft, showing how a ruler can shape history as much by incompetence as brilliance. Augustus's posthumous sobriquet 'The Strong' referred not to any political accomplishment, but to his legendary physical strength and sexual athleticism.

Yet he was also one of the great creative artists of the age, combining driving energy, exquisite taste and apparently boundless resources to master-mind the creation of peerless Dresden, the baroque jewel of jewels. Augustus the Strong brilliantly evokes this time of opulence and excess, decadence and folly.