Complex sentence: Meanwhile, approximately 500 monks who resided in the mountains of Nitria, and who were "of a very fiery disposition", heard of the ongoing feud between the Governor and Bishop and descended into Alexandria armed and prepared to fight alongside Cyril.
Split into simpler sentences: Meanwhile, approximately 500 monks resided in the mountains of Nitria who were "of a very fiery disposition". They heard of the ongoing feud between the Governor and Bishop and descended into Alexandria armed and prepared to fight alongside Cyril.