distance. This entailed major changes in military doctrines, shipbuilding, and professionalism in European navies from the 1650s onwards. The line of battle favored very large ships that could hold the line in the face of heavy fire, later known as ships of the line. The new tactics also depended on the ability of strong, centralized governments to maintain large, permanent fleets led by a professional officer corps. The increased power of the state at the expense of individual landowners led to the expansion of armies and navies, and in the late 1660s Sweden embarked on an expansive shipbuilding program. In 1675, the Swedish fleet was numerically superior to its Danish counterpart (18 ships of the line against 16 and 21 frigates against 11), but it was older and of poorer quality than the Danish fleet, which had replaced a larger proportion of its vessels. The Swedes had problems with routine maintenance, and both rigging and sails were generally in poor condition. Swedish crews lacked the professionalism of Danish and Norwegian sailors, who commonly had valuable experience from service in the Dutch merchant navy, and the Swedish navy also lacked a core of professional officers. The Danish had seasoned veterans like Cort Adeler and Niels Juel. The Danish fleet was also reinforced with Dutch units under the command Philip van Almonde and Cornelis Tromp, the latter an experienced officer who had served under Michiel de Ruyter, famous for his skilled command during the Anglo-Dutch Wars. Prelude A Danish fleet of 20 ships under Admiral Niels Juel put to sea in March 1676, and on 29 April his forces landed on Gotland, which surrendered. The Swedish fleet was ordered out on 4 May with 23 warships of over 50 guns, 21 of less than 50 and 16 minor supporting vessels manned by about 12,000 men, but encountered adverse winds and was delayed until 19 May. Juel had by then left Visby, the main port on Gotland, to join up with a smaller Danish-Dutch force at Bornholm, between the southern tip of Sweden and the northern coast of Germany. Together they intended to cruise between Scania and the island of Rügen to stop Swedish troops from landing on the island and reinforcing Swedish Pomerania. On 25–26 May the two fleets fought the indecisive battle at Bornholm. The Swedish force was superior in numbers but was unable to inflict any serious losses, and two