THE SWEDISH CONNECTION 349
Friedrich Wilhelm (1620-88), the Great Elector, could rise above mere provin-
cial distinction. Thrust into responsibility as a youth of twenty, and swept from
Berlin by the tides of the Thirty Years War, he cultivated his Polish connections
and swore allegiance both to Wladyslaw IV and to Jan Kazimierz. But in 1648
at the Treaty of Westphalia, he was emboldened by the grant of numerous small
territories, including a sliver of Eastern Pomerania, and was encouraged to take
an active part in the subsequent Northern War. In 1656 at the Treaty of Labiau,
he persuaded the Swedes to recognize his claim to independent status as the
price for deserting his Polish suzerain. A few months later, he persuaded the
Polish negotiators to confirm his independence as the price for deserting the
Swedes. Having obtained formal release from his feudal obligations to Poland
at the Treaty of Wehlau (Welawa) on 19 October 1657, he then withheld his
vote in the imperial election until the prospective candidate, Leopold of Austria,
had released Brandenburg from its jurisdictional subordination to the Empire.
Every step was immaculately timed so as to leave the new principality of
Brandenburg-Prussia as one of the principal beneficiaries of the Peace of Oliwa.
Two hundred years after the partition of the Teutonic State, the Great Elector
restored Prussian sovereignty, largely at the expense of the Vasas' Polish
kingdom.
In the last two decades of the Vasa Era, in the sorry reign of Jan Kazimierz, all
the existing strands of internal and external conflict were suddenly twisted
together into a web of strangulating complexity. Cossacks, Tartars,
Muscovites, Swedes, Prussians, and Transylvanians were drawn one by one into
a tightening mesh involving traitorous magnates, rebellious soldiers, religious
dissenters, and international plotters. Jan Kazimierz himself was hardly to
blame. He was a serious and dutiful monarch who succeeded his elder brother
at the age of thirty-nine. Having served as a volunteer in the Habsburg Army, he
was experienced in military affairs; and, as a Jesuit novice and aspirant cardi-
nal, he was no stranger to the religious politics of the age. As a prisoner and
hostage of the French, he knew the perils of international relations at first hand.
Yet he had been personally associated with his brother's rapprochement with
the French court, and was destined to accept his brother's French widow,
Marie-Louise de Gonzagues, in marriage.^21 On the surface, all was set fair for a
prosperous reign. Underneath, an eruption of volcanic proportions was brew-
ing. It all began with the last and greatest of the Cossack rebellions, launched in
the winter of 1647-8 by Bogdan Chmielnicki (1595-1657).^22 (See Map 19.)
The horrors and the pointless waste of the next twenty years were underlined
by the fact that they followed one of the most temperate decades in the
Republic's history. The shock was magnified by the preceding calm. Wladyslaw
IV, ruling since 1632, had contrived to stay aloof from most of Europe's trou-
bles. The Peace of Polanow (1634) with Muscovy, and the Peace of Stumsdorf