A man of war (also man-of-war, man-o'-war or simply man) is an arme naval vessel. The term often refers to a ship armed with cannon and propelled primarily by sails, as opposed to a galley, which is propelled primarily by oars. The man of war was developed in the Mediterranean in the 15th century from earlier roundships with the addition of a second mast to form the carrack. The 16th century saw the carrack evolve into the galleon and then the ship of the line.