4. 11th century
Demographic expansion
The demographic expansion, which may have determined everything else, but must itself be explained - notably perhaps by the wave of progress in agricultural techniques which began in the eleventh century, with the improved
design of the plough, triennial rotation and the open field system for stock farming. Lynn White' regards agricultural progress as of prime importance in the rise of Europe. Maurice Lombard" lays more stress on the progress made in trade: Italy had early links with Islam and Byzantium, and thus came into contact with the already active monetary economy of the East, which she transmitted to the rest of Europe. Towns spelled money, the essential ingredient of the so-called commercial revolution. Georges Duby," and with some reservations Roberto Lopez,21 tend to agree with Lynn White: the vital factor was agricultural overproduction and the large- scale redistribution of surpluses.

A larger population, the perfection of agricultural techniques, the revival of trade and the first wave of craft industry were all essential factors if the area known as Europe was to develop an urban network, an urban superstructure, with inter- city links encompassing all underlying activities and obliging them to become part of a `market economy'. This market economy, though still modest in size, would also lead to an energy revolution, with the widespread use of mills for industrial purposes, eventually creating a world-economy on a European scale. Federigo Melis locates this first Weltwirtschaft within the polygon Bruges- LondonLisbon-Fez- Damascus- Azov-Venice, an area taking in the 300 or so trading cities to and from which the 153,000 letters in the archives of Francesco di Marco Datini, the merchant of Prato, were dispatched. Heinrich Bechtel23 speaks of a quadrilateral: Lisbon- Alexandria- Novgorod-Bergen. Fritz ROrig,24 the first historian to give the meaning 'world- economy' to the German word Weltwirtschaft, suggests that its eastern frontier was a line running from Greater Novgorod on lake Ilmen, to Byzantium. The intensity and volume of trade all contributed to the economic unity of this vast area.
Towns
The town consolidated its future with its roads, its markets, its workshops and the money that accumulated within its walls. Its markets ensured its food supply, as peasants came to town with their daily produce: 'The markets offered an outlet for the growing surpluses of the lordly domains, and for the huge amounts of produce resulting from the payment of dues in kind'.13 According to B. H. Slicher van Bath, after about 115o, Europe moved beyond 'direct agricultural consumption', i.e. self- sufficiency, to the stage of 'indirect agricultural consumption' created by the marketing of surplus rural production." At the same time, the town attracted all the skilled crafts, creating for itself a monopoly of the manufacture and marketing of industrial products. Only later would pre-industry move back into the countryside.
In short, 'economic life . . . especially after the thirteenth century, began to take precedence over the [earlier] agrarian aspects of the towns'.15 Over a very wide area, the crucial move was made from a domestic to a market economy. In other words, the towns were beginning to tower above their rural surroundings and to look beyond their immediate horizons. This was a 'great leap forward', the first in the series that created European society and launched it on its successful career." There is only one event even remotely comparable to this: the creation by the first European settlers in America of the many transit-towns, linked to each other by the road and by the requirements of commerce, command and defence.
This age marked Europe's true Renaissance (for all the ambiguity of the word) two or three hundred years before the traditional Renaissance of the fifteenth century.