28 Wallenstein
James I of England, Frederick’s father-in-law, made public his disap-
proval of the whole affair and would have nothing to do with it. The
French, anti-Habsburg but also Catholic, were preoccupied with their
internal affairs, as were the Protestant Scandinavian kings. Savoy and
Venice were too prudent to become further involved, Brandenburg was
too poor and too timorous, and John George of Saxony in due course
sided with the emperor. The only practical military help came from
Bethlen Gabor, the Calvinist prince of Transylvania, in modern terms
north-west Romania but then an independent principality, although
nevertheless a tributary of the Ottoman Empire. Bethlen had his own
ambitions and reasons for becoming involved, which fitted into the
long-term pattern of recurrent outbreaks of war between the emperor
and the Turkish dependencies on the Austro-Hungarian frontier. To the
extent that his interests coincided with theirs Bethlen provided valuable
assistance to the Protestant side in the early part of the Thirty Years War,
but he proved to be an unreliable ally, prone to concluding truces with
the Habsburgs whenever he faced pressures elsewhere or when his own
objectives had been achieved.
In the spring of 1619 Ferdinand was almost equally isolated militarily.
The forces he had put into the field with Spanish assistance the previ-
ous autumn had fared badly, and moreover he was faced with actual or
potential rebellion not only in the Bohemian territories but also from
Protestant majorities in much of his Austrian heartland, with even
Vienna far from reliable. Thurn, following on from his bloodless triumph
in Moravia, took advantage of the situation to march into Austria, and
by May he had the capital itself under siege. In early June there was a
change of fortune. Bucquoy caught Mansfeld and the larger part of his
army, defeating him heavily near the town of Záblatí, the first significant
Imperialist victory and one which immediately caused the Bohemian
Estates to recall Thurn, so that the siege of Vienna was lifted.
The respite was short-lived, as in August Bethlen launched his attack
through Habsburg Hungary towards Pressburg (Bratislava), which he
captured in October to bring him within striking distance of Vienna.
Bucquoy was called back to the defence, and hotly pursued by Thurn he
made a hazardous withdrawal over the Danube at Ulrichskirchen, not
far from Vienna, but was unable to prevent Thurn and Bethlen joining
forces to besiege the city for a second time. Again the siege was aban-
doned, as towards the end of November Bethlen heard of a diversion-
ary Polish foray into Transylvania, and this and the approach of winter
were sufficient to send him home. Thurn, short of money and artillery,
his troops ill paid, ill disciplined, and ill from various pestilences, had