Lateen sail

A lateen is a triangular sail set on a long yard mounted at an angle on the mast and running fore and aft; it originated in the Mediterranean as early as the 2nd century CE, in Roman times. It became common there by the 5th century and by the 6th had largely replaced the square sail, a change suggested to have been made on cost grounds, as the two rigs performed much alike. Arab seafarers adopted it after the Muslim conquests, and it later rigged caravels and the mizzens of full-rigged ships.