Walker - 1967 - A geography of Italy

ITALY DURING THE MIDDLE AGES
Brenta was straightened and controlled by levees, and about 1300 the Po was
newly dyked from its jimction with the Oglio to Ostiglia. On higher ground above
the fens where irrigation was possible the Cistercians built the Chiaravalle Canal
near Milan and the commune o f that city had completed the La Muzza Canal by
1239 and the Naviglio Grande soon after. In 1400 the Milan-Pavia Canal was
constructed by the orders o f Gian Galeazzo Visconti. Reclamation was not confined
to the Po Valley; much of the fen round Lucca was drained; attempts, albeit
unsuccessful, were made to reopen the Roman conduits draining Lake Fucino in
1240; Popes Boniface V III and Martin V made efforts to reclaim parts o f the
Pontine Marshes; and in 1341 by digging chaimels to the Arno the commune of
Arezzo began the long struggle to drain the Val di Chiana to the north. The
industrial cities were a great stimulus to agriculture; they drained off the surplus
rural population, provided the drive and money for reclamation, and encouraged
the intensive cultivation o f foodstuffs and raw materials, e.g. Romagna flax and
hemp, Sicilian and Calabrian silk, Abruzzi wool and saffron. The intensification
demanded in the neighbourhood o f the big towns was made possible not only by
the natural fertility o f the alluvial soils, but also because irrigation enabled large
numbers of livestock to be kept which provided the manure, the lack of which
had always been a problem in the purely Mediterranean area farther south.
Green maniu-ing, too, was advocated as early as the thirteenth century by Pietro
dei Crescenzi. In contrast to the South where feudal tenures were more firmly
established, many cultivators in north-central Italy were virtually peasant
proprietors by the thirteenth century. Mezzadria in various forms also became
increasingly widespread in the Middle Ages. The demesne land was usually
worked by tenants who paid higher rents for the privilege, and then, as now, the
33