A Letter of Marque is a government license that authorizes a private individual or ship, known as a privateer, to attack and capture enemy vessels during wartime. This practice allowed nations to bolster their naval power without maintaining a large standing fleet, as privateers operated under the authority of the state. Historically, Letters of Marque were issued by various countries, including England and France, particularly during the Age of Sail. They played a significant role in maritime conflicts, enabling privateers to profit from their captures while also serving national interests in naval warfare.