A military action near this city, which was defended by the Linienwall, legendarily resulted in the invention of the bagel and the croissant. Charles of Lorraine and Leopold I held onto this city at a battle fought on Kahlenberg Mountain. Viscount Castlereagh ("KASS-ul-rey") represented Britain and 
A military action near this city, which was defended by the Linienwall, legendarily resulted in the invention of the bagel and the croissant. Charles of Lorraine and Leopold I held onto this city at a battle fought on Kahlenberg Mountain. Viscount Castlereagh ("KASS-ul-rey") represented Britain and helped forge a quadruple alliance at one meeting in this city. Jan Sobieski arrived to defend this city from janissaries. A congress in this city, which organized post-Napoleonic Europe, was led by Prince Metternich. For 10 points, name this city besieged twice by the Ottomans, the seat of the Habsburgs' Austro-Hungarian empire.
A military action near this city, which was defended by the Linienwall, legendarily resulted in the invention of the bagel and the croissant.
City of Vienna [or Stadt Wien] 