 It was as agriculturists and horse and cattle breeders that the Cistercians exercised their chief influence on the progress of civilisation in the Middle Ages.As the great farmers of those days, many of the improvements in the various farming operations were introduced and propagated by them, and this is where the importance of their extension in northern Europe is to be estimated.They developed an organised system for selling their farm produce, cattle and horses, and notably contributed to the commercial progress of the countries of western Europe.