During the Muslim conquests of the 7th century, Arab fleets first appeared, raiding Sicily in 652 (see History of Islam in southern Italy and Emirate of Sicily), and defeating the Byzantine Navy in 655. Constantinople was saved from a prolonged Arab siege in 678 by the invention of Greek fire, an early form of flamethrower that was devastating to the ships in the besieging fleet. These were the first of many encounters during the Byzantine-Arab Wars.