Amid the many motives which led Europeans to take part in the overseas movements of the fifteenth and sixteenth centuries, the need to provide some overspill for redundant population was negligible. Men wished, perhaps, to strike the infidel a blow, to strengthen their native state, to ascertain the shape and the nature of the earth, to gain great wealth or to escape from a humdrum existence—or perhaps a mixture of these things. Seldom was the hope of access to the trade goods, the spices and the silks and cotton of the sophisticated East far from their minds. But they neither wished to settle overseas themselves to earn their livings in alien lands nor to provide opportunity for their compatriots to do so. They were not colonizers, but, usually, traders or would-be traders. The desire to colonize, to settle or even to organize production, came late, and was accepted reluctantly.

Any estimate of the population of Europe as it came into the modern age, still more of the different states of Europe which were becoming increasingly the effective units, must be largely a matter of guesswork in which such data as the number of hearths, of communicants, of shipowners, of serviceable military men or even of corpses, are subjected to multipliers and distributors. Figures got by such processes can be closely related to contemporary estimates, but they remain slightly conjectural, and they are largely irrelevant from the point of view of overseas expansion. The general picture, however, has begun to emerge with reasonable clarity and to gain in significance. It is a picture which starts with a widespread and catastrophic decline in population in the fourteenth century and in which any sustained recovery was delayed by endemic plagues and constant warfare until the last quarter of the fifteenth century.