Edward I was the first English monarch to tax the wool trade–to help pay, as always, for his wars.

Sheep have been herded in Wales since possibly the Celts, though it is difficult to pinpoint exactly when sheep first came to Wales.  “Excavations show that in about 6000 BC, during the Neolithic period of prehistory, the Castelnovien people, living around Chateauneuf-les-Martigues near present-day Marseille in the south of France, were among the first in Europe to keep domestic sheep. Practically from its inception, ancient Greek civilization relied on sheep as primary livestock, and were even said to name individual animals. Scandinavian sheep of a type seen today — with short tails and multi-colored fleece — were also present early on.

Later, the Roman Empire kept sheep on a wide scale, and the Romans were an important agent in the spread of sheep raising throughout the continent. Pliny the Elder, in his Natural History (Naturalis Historia), speaks at length about sheep and wool.  Declaring “Many thanks, too, do we owe to the sheep, both for appeasing the gods, and for giving us the use of its fleece.”  He goes on to detail the breeds of ancient sheep and the many colors, lengths and qualities of wool. Romans also pioneered the practice of blanketing sheep, in which a fitted coat (today usually of nylon) is placed over the sheep to improve the cleanliness and luster of its wool.

During the Roman occupation of the British Isles, a large wool processing factory was established in Winchester, England in about 50 AD.  By 1000 AD, England and Spain were recognized as the twin centers of sheep production in the Western world.” (See Wikipedia http://en.wikipedia.org/wiki/Sheep#In_Europe for citations)

“Wool became the backbone and driving force of the medieval English economy between the late thirteenth century and late fifteenth century and at the time the trade was described as “the jewel in the realm”! To this day the seat of the Lord High Chancellor in the House of Lords is a large square bag of wool called the ‘woolsack’, a reminder of the principal source of English wealth in the Middle Ages.

As the wool trade increased the great landowners including lords, abbots and bishops began to count their wealth in terms of sheep. The monasteries, in particular the Cistercian houses played a very active part in the trade, which pleased the king who was able to levy a tax on every sack of wool that was exported.

From the Lake District and Pennines in the north, down through the Cotswolds to the rolling hills of the West Country, across to the southern Downs and manors of East Anglia, huge numbers of sheep were kept for wool. Flemish and Italian merchants were familiar figures in the wool markets of the day ready to buy wool from lord or peasant alike, all for ready cash. The bales of wool were loaded onto pack-animals and taken to the English ports such as Boston, London, Sandwich and Southampton, from where the precious cargo would be shipped to Antwerp and Genoa.”  http://www.historic-uk.com/HistoryUK/England-History/wooltrade.htm

John Davies writes, in his History of Wales, in regards to the newly formed chain of Cistercian monestaries in Wales:  ” . . . for the monks were granted thousands of hectares of grazing land, where they pioneered the Welsh woollen industry; there is very little evidence that sheep were important to the Welsh economy before the coming of the Cistercians” (2007:126).

It certainly became important as The Welsh National Wool Museum can attest:  http://www.museumwales.ac.uk/en/wool/

“Power notes three breeds as accounting for most wool production in the Middle Ages, Ryeland, Cotswold and Lincoln. Ryeland was the most famous of short-woolled breeds, grown in the country between the Severn and the marches of Wales, and was largely responsible for the ‘Lemster ore’, the golden fleece of England. The bulk of the fine wool exported in the Middle Ages came from two long-woolled breeds, however, Cotswold and Lincoln and in the fifteenth century the largest source of fine wool seems to have been the Cotswolds.”  http://www.wildfibres.co.uk/html/sheep_history.html