wing population makes conditions
intolerable, youths are chosen, perhaps by religious rites, to
adventure, sword in hand, and carve out new territory or die fighting.
There are always more than there is place for, and it is always
possible for a young Fortinbras to shark up "a list of {23} lawless
resolutes for food and diet, to some enterprise that hath a stomach in
't." All the interminable battling of the early Middle Ages reveals
this effort of fecund agricultural populations to solve the problem of
over-breeding by slaughter.

Even the Crusades partake of this economic character. Among the
Crusaders were exalted souls, who wished to rescue their Lord's
sepulchre, but there were many more who dreamed of free lands, gold and
silver, and the beautiful women of the Orient. The religious motive
was present; it was strong and intolerant, though it did not in the
later Crusades prevent Christians from attacking Christians. At
bottom, however, certain strong economic factors forced on the
struggle. There had been famine in Lorraine and pestilence from
Flanders to Bohemia, and all the discontent, hunger and ambition of
western Europe answered to Urbano's call. "A stream of emigration set
towards the East, such as would in modern times flow towards a newly
discovered gold-field--a stream carrying in its turbid waters much
refuse, tramps and bankrupts, camp-followers and hucksters, fugitive
monks and escaped villains, and marked by the same motley grouping, the
same fever of life, the same alternations of affluence and beggary,
which mark the rush for a gold-field to-day."[1] Not until it was seen
that they no longer paid did the Crusades end; not heavenly but earthly
motives inspired most of these soldiers of Christ. It was business,
the business of a crudely organised, over-populated, agricultural
Europe.

Even with the development of commerce, the motive does not change in
character, though its form becomes different. All through history we
find maritime cities and states fighting for the control of trade
routes, the exploitation of {24} markets and peoples, the right to sell
goods and keep competitors from selling. Athens, Venice, Genoa, Pisa,
Florence, Holland, England--it is all the same story. Undoubtedly,
with the development of commerce, wealth takes a new form. Land is no
longer the sole wealth, and successful warriors need no longer be paid
in land and live off the land, as they are forced to do in ev