‘Eclipsis Poloniae’ was a phrase used by a leading statesman of the time, Stanislas Szczuka, vice-chancellor of Lithuania, to describe the condition of the Polish Commonwealth at the beginning of the eighteenth century. It would have been hard yet to talk of the ‘collapse’ of a State which still had a place in every European constellation, and whose favours were still courted by powers which themselves were facing great internal changes. This was not yet the period when Poland, narrowly controlled by powerful neighbours, would be the helpless butt of other people's politics. On the other hand, increasing anarchy was already preventing the Commonwealth (Rzeczpospolita) from exploiting such political opportunities as came its way. Contemporaries held that this was only the temporary eclipse of a State which until recently had been powerful. If by 1721 the long years of war were a thing of the past in this part of Europe, so too was the former balance of power between its various States. The Habsburgs were immensely strengthened by their control of Hungary and by their succession in Italy and the Low Countries. Russia, following the Petrine reforms and her conquests on the Baltic coast, had grown into the leading power in the North. In Prussia rigorous government was building the foundations of militarism. At the same time, Sweden had ceased to count and Turkey was capable of active policy only by fits and starts. Poland, restricted in scope for diplomatic manoeuvre and penalized by the interference of dominant neighbours, sank into the deepest gloom of the so-called Saxon era.