A well-known characteristic of the mountain regions of southern Europe in the preindustrial period was the regular movement of young migrants who left each winter to seek work in the lowlands and returned in the spring as the snows melted. This response became an established and lasting feature of the economies of upland areas from the period of demographic recovery following the Black Death. For most scholars the iconography of such movement helped to define the human ecology of mountain areas. In conditions closest to the margins of existence, the main function of such migration, it seemed, was to ease the pressure on subsistence – though those returning might be expected to bring back a little capital to help pay taxes (Dupâquier, 1988; Braudel, 1966, pp. 33, 42, 46, 272–74; 1979, pp. 78, 79; 1990, pp. 244, 301, 302, 509, 510; Le Roy Ladurie, 1966, pp. 98–102; Hufton, 1974, p. 72; Poitrineau, 1981; Perrel, 1966; Moch, 1983, pp. 33, 34; Viazzo, 1989, chs 1–6).

Recent demographic research reveals that this regular movement was certainly significant, leaving its mark on the periodicity of marriages and births, as young men left in the autumn and returned again in the spring. In some circumstances it may also have regulated fertility (Maistre and Maistre, 1986, p. 101; Jones, 1990; Reher, 1990, ch. 3). It seems at least reasonable to infer, however, that such seasonal movements were no more than a minor brake on increasing population. When harvests were good, these healthy mountain environments, perhaps isolated from the worst effects of epidemics and plagues which affected lowland areas, developed demographic regimes characterized by relatively high nuptiality, potentially high fertility, good life expectancy and relatively low death rates (Jones, 1990; Collomp, 1988; 1984, pp. 145–70; Viazzo, 1989, pp. 215–19). While it is wise to remain cautious about this kind of generalization, these populations certainly had the potential to expand quite rapidly during periodic ameliorations of climate, especially where they were encouraged (or unrestrained) by seigneurial authority. Here they could clear new land for cultivation and increase the size of their animal herds and flocks, eventually to press against the new ecological margins that the more temperate conditions had exposed.