The Königsberg fortifications were erected due to the vulnerability during which war of 1563-1721?
Königsberg fortifications The fortifications of the former East Prussian capital Königsberg (now Kaliningrad) consist of numerous defensive walls, forts, bastions and other structures. They make up the First and the Second Defensive Belt, built in 1626—1634 and 1843—1859, respectively. The 15 metre-thick First Belt was erected due to Königsberg's vulnerability during the Polish–Swedish wars. The Second Belt was largely constructed on the place of the first one, which was in a bad condition. The new belt included twelve bastions, three ravelins, seven spoil banks and two fortresses, surrounded by water moat. Ten brick gates served as entrances and passages through defensive lines and were equipped with moveable bridges.
Siege of Gaeta (1707) The siege of Gaeta was a three-month siege of the Italian city of Gaeta in 1707 by the forces of the Austrian monarchy under Wirich Philipp von Daun, during the War of the Spanish Succession. It ended on 30 September with the total destruction of the city's historic fortifications.