Work in the fields
The 11th and 12th centuries mark the period when man attained mastery of the land. In Normandy, the increase in the cultivated acreage as compared with the old terroirs" lay somewhere between 20 and 50%. The wealthiest and most populated regions seem still to have been in the plains cleared since Roman times, where it was easiest to grow cereals - the plain around Caen, the coastal plains of the Bessin and the eastern Cotentin, the Pays de Caux, and the rich plains of the Eure department on a fiercely disputed border with the King of France.
The "bocage" or hedgerow regions were cleared more recently, but that precisely was the great economic development of the 11th and 12th centuries. This advance was the result, not of immigration or colonisation, but of individuals or family groups settling on new land. We find traces of this in local place-names, where the suffix "-ière" or "-érie" is added to a family name.
Such mastery of the land was made possible by technological advances. Archaeological excavations have shown how the use of iron for making all kinds of tools became more common during this period. The Bayeux Tapestry contains evidence that Normandy was ahead of its time in the use of certain techniques such as teams of horses as an alternative to oxen for tilling, the use of ploughs with a front wheel, or the technique of harrowing.
The Norman peasants also knew how to use soil improvement techniques, such as marling in the Pays d'Auge and the Pays d'Ouche, or the use of "tangue", a natural fertilizer produced by the build-up of silt in the marshy estuaries of the Cotentin and the Bessin.
The water mill was used to grind the grain as well as for various craft industries (tanner's mills, fuller's mills). Lastly, the Normandy of the dukes saw the introduction of one major innovation, probably from the east, the windmill, attested in the Cotentin (Montmartin-en-Graignes) in 1180.
Normandy in this period acquired a reputation for mostly agriculturally-based wealth that was the envy of many. The province was the jewel in the crown of the Plantagenets and provided her early 13th century master, the King of France with a quarter of his income.