Privateers constituted a large proportion of the total military force at sea during the 17th and 18th centuries. During the Nine Years War, the French adopted a policy of strongly encouraging privateers (French corsairs), including the famous Jean Bart, to attack English and Dutch shipping. England lost roughly 4,000 merchant ships during the war. In the following War of Spanish Succession, privateer attacks continued, Britain losing 3,250 merchant ships. During the War of Austrian Succession, Britain lost 3,238 merchant ships and France lost 3,434 merchant ships to the British.