Pls pls help for this question :What word should go where the question mark is ?

“the iliad” (gr: “iliás”) is an epic poem by the ancient greek poet homer, which recounts some of the significant events of the final weeks of the trojan war and the greek siege of the city of troy (which was also known as ilion, ilios or ilium in ancient times).

it made them more prductive and efficent but with the change of polcies less and les got into the navy