the needs of the fleet: seventeen iron (local marsh ore), eleven anchor, twelve nail, ten cannon, ten rifle, two steel, seven metal, eight copper smelting (imported, African), three canvas rope, five powder, twenty-nine sawmills and woodworking, and dozens of tar booths. By the end of the 1650s, Courland and Semigallia had more than 40 warships armed with 15–72 guns, as well as about 80 merchant ships, mostly . The navy was commanded by the Dutch Admiral Imke, and the merchant Heinrich Mober. Warships were used to protect the merchant navy from pirates – to protect the Courland colonies in Tobago and at the mouth of the Gambia. The entire fleet was headed by the Vindava Admiralty. The Second Northern War with the Swedes of 1658–1660 dealt a great blow to the fleet of Courland and Semigallia. Betrayed by his hopes for neutrality, Jacob was invaded by the Swedes and taken prisoner with his family. The attackers burned the Courland shipyards and manufactories, killed many craftsmen, and took some of the ships and specialists to Sweden. After the Peace of Oliva, Jacob regained the duchy and tried to revive the country's economy, but did not reach the pace of pre-war production. During his reign, Duke James built 65 warships and 130 merchant ships, which was incredible for that time, especially for such a small state. The duke sometimes rented ships. Thus, in 1648, the government of the Venetian Republic was indebted to Jacob for using the services of Courland ships. Decline The decline of the fleet of Courland and Semigallia began with the reign of Frederick Casimir, son of Jacob. The generous duke led a lavish lifestyle, was interested in entertainment rather than ships, and therefore sold most of the state-owned manufactories founded by his father for cash. He stopped the production of warships at shipyards, sold large ships, and sold the colonies to the British. Before the Great Northern War, the duchy had only 15 ships. In 1702 the Goldingen and Libava shipyards were closed, and in 1718 the Vindava shipyards suffered the same fate. Ships In times of illiteracy—among both commanders and sailors—instead of the name of the ship on board, a coat of arms or other image was placed on the stern. Sometimes it was supplemented by a signature, usually Latin. It could be the name or motto of the vessel. Accordingly, the same ship could be mentioned