Between 1640 and 1786 four generations of Hohenzollern rulers transformed Prussia from a collection of scattered and loosely combined provinces into a European Power. The labours of Ranke, and of the German scholars who continued his work in the Prussian State archives, particularly Schmoller, Hintze and Hartung, have left us in little doubt as to ‘how things really were’ in the field of internal administration in this century and a half, and the evidence can readily be checked in the well-edited volumes of the Acta Borussica. About the personalities of the Great Elector, King Frederick William I and Frederick the Great, and their claims to the admiration and imitation of later generations, the views expressed by historians have naturally been as various as their political backgrounds and ethical convictions, but it is generally agreed that among the presuppositions governing the actions of these monarchs three were never questioned: that kingship is a sacred trust, that authoritarianism is the only rational form of government and that its primary aim is the increase of the power of the State. ‘The happiness of the king's subjects does indeed appear alongside power [in the political testament of Frederick the Great], but the spirit which governs the whole system is that of power politics, not welfare legislation.’

To appreciate the achievements of the Prussian rulers we must remember what they started from in 1713. Brandenburg-Prussia was then one of the many composite ‘territories’ which, along with many smaller and some very small States, went to make up the ramshackle Holy Roman Empire.