sentences:  The difficulties of Charles X in Poland are believed to have caused him to receive the tidings of the Danish-Norwegian declaration of war on 1 June 1657 with extreme satisfaction.He had learnt from Torstensson that Denmark was most vulnerable if attacked from the south, and he attacked Denmark with a velocity which paralysed resistance.At the end of June 1657, at the head of 8,000 seasoned veterans, he broke up from "Bromberg" (Bydgoszcz) south of Pomerania and reached the borders of Holstein on 18 July.