The conquest of Silesia, carried out only a few months after his accession, was undoubtedly the most significant act of Frederick the Great’s life. Its importance and repercussions have been analysed for many generations by German and non-German historians. It has been lauded, on the one hand, as the historic moment of Prussia’s emergence as a great power and condemned, on the other, as a violently aggressive and morally reprehensible action. However much this event is open to widely divergent interpretations, the facts surrounding it have been established down to the last detail and new discoveries are no longer possible. In Borussian and later German nationalist historiography it has assumed almost legendary status, and it is up to the historian to dispel the myth. The opponents of Prussia and its rise to great power status, be they partisans of an Austrian-centred ‘greater Germany’ interpretation, or the outraged exponents of morality founded in natural law, saw the events of 1740/41 as an act of calculated criminality. Over two hundred years later, after the fall of Prussia and the disappearance of German Silesia, and the rise and fall of a new German dualism which rendered the Prusso-Austrian rivalry redundant, even events which have been thoroughly analysed can be reinterpreted. New questions, which even fifty years ago would not have been asked, have arisen and demand fresh answers. Old interpretations no longer accord with the present, and the demands upon history to legitimate the rights of the Prussian monarchy and the Prusso-German state are irrelevant. No historian would now interpret the past in terms of later events.