The Jewish emigration from Western Europe assumed especially large proportions in the first part of the fourteenth century. The butcheries perpetrated by the hordes of Rindfleisch and Armleder, and the massacres accompanying the Black Death, forced a large number of German Jews to seek shelter in Poland, which was then undergoing the process of unification and rejuvenation. In 1319, King Vladislav[28] Lokietek[29] laid the foundation for the political unity of Poland by abolishing the former feudal divisions, and his famous son Casimir the Great (1333-1370) was indefatigable in his endeavors to raise the level of civil and economic life in his united realm. Casimir the Great founded new cities and fortified old ones, promoted commerce and industry, and protected, with equal solicitude, the interests of all classes, not excluding those of the peasants. He was styled the "peasant king," and the popular commendation of his efforts in the upbuilding of the cities was crystallized in the saying that Casimir the Great "found a Poland of wood and left behind him a Poland of stone." A ruler of this type could not but welcome the useful industrial activity of the Jews with the liveliest satisfaction. He was anxious to bring them in close contact with the Christian population on the common ground of peaceful labor and mutual helpfulness. He was equally quick to appreciate the advantages which the none too flourishing royal exchequer might derive from the experience of Jewish capitalists. Such must have been the motives which actuated Casimir when, in the second year of his reign (1344), he ratified, in Cracow, the charter which Boleslav of Kalish had granted to the Jews of Great Poland, and which he now extended in its operation to all the provinces of the kingdom.