Complex sentence: The Cluniac and Cistercian Orders were prevalent in France, the great monastery at Cluny having established a formula for a well planned monastic site which was then to influence all subsequent monastic building for many centuries.
Split into simpler sentences: The Cluniac and Cistercian Orders were prevalent in France. The great monastery at Cluny established a formula for a well planned monastic site that influenced subsequent monastic building for many centuries.