Complex sentence: The rebel attack was launched from three directions at around 2:30 a.m and achieved a degree of surprise, driving the garrison back to a barricade outside the gaol, on a slight hill at the centre of the town's main street.
Split into simpler sentences: The rebel attack was launched from three directions at around 2:30 a.m, achieving a degree of surprise. The onslaught drove Naas'garrison to a barricade outside the gaol which was located on a slight hill at the centre of the town's main street.