" Impoverished Spain depended on imports not only for manufactured products but even for sufficient food. Spanish agriculture was hampered by poor soil and by the strange institution known as the Mesta. Spanish sheep grew high-quality fleeces—not as good as those of English sheep but better than could be found elsewhere—and Spain had, in fact, replaced England as the source of wool for the Flemish and Italian cloth industries. The Mesta was an organization of sheep owners who had royal privileges to sustain migratory flocks of millions of sheep. The flocks moved all across Spain—north in the summer, south in the winter—grazing as they went, making it impossible to farm along their routes.42 When conflicts arose with landowners, the crown always sided with the Mesta on grounds that nothing was more important to the economy than the wool exports. The government’s protection of the Mesta discouraged investments in agriculture, so Spain needed to import large shipments of grain and other foodstuffs. "
― Rodney Stark , How the West Won: The Neglected Story of the Triumph of Modernity