Complex sentence: After long study and meditation, Ammonius opened a school of philosophy in Alexandria, where his principal pupils were Herennius, the two Origens, Cassius Longinus and Plotinus.
Split into simpler sentences: After long study and meditation, Ammonius opened a school of philosophy in Alexandria. His principal pupils were Herennius, the two Origens, Cassius Longinus and Plotinus.