Complex sentence: After withdrawal from Ctesiphon, the Persian armies gathered at Jalula north-east of Ctesiphon, a place of strategic importance from where routes led to Iraq, Khurasan and Azerbaijan.
Split into simpler sentences: After withdrawal from Ctesiphon, the Persian armies gathered at Jalaula north-east of Ctesiphon. Jalaula was a place of strategically importance from where routes led to Iraq, Khurasan and Azerbaijan.