Complex sentence: Having cleared a way through, they crossed the gorge and galloped into the city with drawn swords, passed a barracks containing thousands of soldiers who did not interfere with their movements, but the streets were filling with people who forced them to slow to a walk.
Split into simpler sentences: Having cleared a way, they crossed the gorge and galloped into the city with drawn swords. In the process they passed a barracks containing thousands of soldiers who did not interfere with their movements, but the streets were filling with people who forced them to slow to a walk.