What was the most important issue contributing to the great schism

the answer is lower nubia. plz mark brainliest i am trying to improve rank.

“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).