The Vasa was built during the 30 Years' War of 1618-1648, when Sweden had lost a dozen ships and needed vessels to support King Gustav II Adolph's military campaign in the Baltic. The ship was the largest in the history of the Swedish fleet, with an extra cannon deck that the king himself had ordered during the Vasa's construction. On August 10, 1628, the vessel departed from her mooring in front of the royal palace with some 130 crewmen and wives on board. As she sailed slowly through the islands that separate Stockholm from the open sea, a wind caught the sails, and the top-heavy ship unexpectedly hove to port. Water poured through the open cannon ports, and the ship sank in the 105-foot (32-meter) channel.