Complex sentence: The situation deteriorated with each passing day, and soon descended into full-blown civil war: there were several tens of battles fought per day in the alleys or market at its peak, on one occasion the emperor's own tent being caught in the crossfire.
Split into simpler sentences: The situation deteriorated with each passing day, and had descended into full-blown civil war. There were several tens of battles fought per day in the alleys or market at its peak, on one occasion the emperor's own tent being caught in the crossfire.