Excerpts from Books and Wikipedia
Vienna was saved by Polish King Jan Sobieski, whose army arrived on September 11 and defeated the Ottoman Turks on September 12. This was the end of the Ottoman threat in Christian Europe. [Furtado: 1001 Days] "Also collective was the great building-boom that took place in the wake of the defeat of the Turks and their subsequent expulsion from Hungary. Now that it was safe to build, the aristocrats of the Monarchy set to work with a will: in the half-century after 1683 around 300 palaces were constructed in and around Vienna. . . . By 1700 at the latest, Vienna was the undisputed premier playground of the nobility of both the Habsburg Monarchy and the Holy Roman Empire." [Blanning: Pursuit of Glory, p. 449-50]