In admiralty law prizes are equipment, vehicles, vessels, and cargo captured during armed conflict. The most common use of prize in this sense is the capture of an enemy ship and her cargo as a prize of war. In the past, the capturing force would commonly be allotted a share of the worth of the captured prize. Nations often granted letters of marque that would entitle private parties to capture enemy property, usually ships. Once the ship was secured on friendly territory, she would be made the subject of a prize case: an in rem proceeding in which the court determined the status of the condemned property and the manner in which the property was to be disposed of. In his book The Prize Game, Donald Petrie writes, "at the outset, prize taking was all smash and grab, like breaking a jeweler's window, but by the fifteenth century a body of guiding rules, the maritime law of nations, had begun to evolve and achieve international recognition." Grotius's seminal treatise on international law called De Iure Praedae Commentarius (Commentary on the Law of Prize and Booty), published in 1604—of which Chapter 12, "Mare Liberum" inter alia founded the doctrine of freedom of the seas—was an advocate's brief justifying Dutch seizures of Spanish and Portuguese shipping. Grotius defends the practice of taking prizes as not merely traditional or customary, but just. His Commentary claims that the etymology of the name of the Greek war god Ares was the verb "to seize", and that the law of nations had deemed looting enemy property legal since the beginning of Western recorded history in Homeric times. Prize law fully developed between the Seven Years' War of 1756–1763 and the American Civil War of 1861–1865. This period largely coincides with the last century of fighting sail and includes the Napoleonic Wars, the American and French Revolutions, and America's Quasi-War with France of the late 1790s. Much of Anglo-American prize law derives from 18th Century British precedents – in particular, a compilation called the 1753 Report of the Law Officers, authored by William Murray, 1st Earl of Mansfield (1705–1793).