On 10 July 1655, Charles X left Sweden to engage in a war against the Polish–Lithuanian Commonwealth, in what became the Second (or Little) Northern War (1655–1660). By the time war was declared he had at his disposal 50,000 men and 50 warships. Hostilities had already begun with the occupation of Dünaburg in Polish Livonia by the Swedes on 1 July 1655. Then on 21 July 1655 Swedish army under Arvid Wittenberg crossed into Poland and proceeded towards the encampment of the Greater Poland Levy of the Nobility (pospolite ruszenie) encamped among the banks of the Noteć river, with some regular infantry for support. On 25 July the Polish noble levy army capitulated, and the voivodeships of Poznań and Kalisz placed themselves under the protection of the Swedish King. Thereupon the Swedes entered Warsaw without opposition and occupied the whole of Greater Poland. The Polish king, John II Casimir of Poland (1648–68) of the House of Vasa, eventually fled to Silesia after his armies had suffered defeats. A great number of Polish nobles and their personal armies joined the Swedes, including the majority of the famous Winged Hussars. Many Poles saw Charles X Gustav as a strong monarch who could be a more effective leader than John II Casimir.