"They knew VERY WELL about the Barbary pirates, the Saracens and the Turk."
'They' should have read the book by Sir William Muir: The Caliphate:Its Rise Decline and Fall.
It traces the history of islam from the death of the 'prophet' until the conquests and expansion of islam in Arabia, the Near East, Iran, North Africa and Spain.
The entire 602 pages are filled with nothing but slaughter.