answer:There have been pirates since before the Common Era. The Mediterranean had pirates in various places that preyed upon Roman and Greek and Phoenician ships. And the China Seas have been rife with pirates for millennia. Knights in Western Civilization were a form of cavalry to serve medieval nobles. So in the common connotation they were from the 6th Century through the middle of the Renaissance. But remember that there was an order of knights in the Roman Empire, an order of equestrians founded by Romulus, the Equites. So while piracy was banditry that has existed probably back to the days of Egyptian glory, Knights were found at about the same time.