for their exploitation of the East Indies, in fact, their Baltic trade was more profitable in absolute terms. Also, the Republic was critically dependent on Scandinavian wood to build ships and Polish grain to feed its large urban population. When Charles conquered Poland, Amsterdam under his regent Cornelis de Graeff supported the subsequent rebellion and sent Obdam with a fleet to relieve Danzig in 1656 In 1657, van Wassenaer blockaded Lisbon and captured fifteen ships of a Portuguese sugar fleet, but, in 1658, had to return to the Baltic as the situation there had grown even more critical. After the failure of his Polish campaign Charles had turned his attention on Denmark and had invaded Jutland from Germany. He then made peace with Frederick III of Denmark but treacherously broke it a few weeks later in an attempt to take Copenhagen by assault. This failed and he laid siege to the Danish capital, the last part of his kingdom still under Frederick's control. After much deliberation the States-General decided to send the entire active Dutch fleet and a mercenary army to relieve the Danes. On 8 November 1658, the Dutch defeated the heavier Swedish ships in the Battle of the Sound. During this battle, Witte de With who commanded the Dutch van was first to attack the Swedes, but his ship was boarded and he was killed, although his captured ship sank almost immediately. Van Wassenaer commanding the centre and the whole fleet in the Dutch flagship Eendragt attacked the Swedish commander, Gustaf Wrangel, and was, in turn, attacked and surrounded by several Swedish ships and only got clear after several Dutch ships came to his aid. Much of the direction of the Dutch attack resulted from the tactical skill of Van Wassenaer's flag captain Egbert Bartholomeuszoon Kortenaer, whose presence was missed in later battles when he was promoted to flag rank. Van Wassenaer remained in command of the Dutch fleet during the winter of 1659. however, as the Swedes had been reinforced by a strong English fleet under Edward Montague giving this combined fleet superiority, ne remained largely inactive until reinforced by a squadron commanded by Vice-Admiral De Ruyter. In the summer of 1659, Obdam, de Ruyter and Johan Evertsen, either jointly or in separate squadrons assisted in the liberation of the Danish Isles, greatly assisted by the withdrawal of the English fleet. Van Wassenaer and most of the