(Cambridge Concise Histories) Jerzy Lukowski, Hubert Zawadzki - A Concise History of Poland-Cambridge University Press (2006)

Domestically, Poland needed stability, which could only come about by strengthening royal authority. Externally, the new king had not only to resolve relations with the Ordensstaat and the House of Luxemburg, he had to deal with a power vacuum on Poland’s south-east borders, which threatened to embroil him with the Tatars and with Lithuania. Poland continued to lie in the shadow of the Hungarian Angevins, first, of Casimir’s brother-in-law, Charles I Robert, and then his nephew Louis the Great (1342-82), both of whom had their own designs on the Polish throne. The realm, the ’Crown’ as it was styled by his jurists -Corona Regni Poloniae - that Casimir ruled, a narrow and irregular lozenge of territory, spilled from north-west to south-east on either side of the Vistula; with probably fewer than 800,000 inhabitants, it contained less than half the territories and population that might plausibly have been called Polish. Against the Knights, Casimir was largely on his own. The Angevins wanted good relations with them in their own struggles against the

Wittelsbachs and the I.uxemburgs. Poland was to be kept in its subordinate place. The treaty of Kalisz of 8 July 1343 was a ‘compromise’ which benefited the Knights. They restored the vulnerable border territories of Dobrzyn and Kujawy lost by Tokietek, but kept what they really wanted - Gdansk and Pomerania. Casimir also had to face up to the loss of Silesia. In 1348, John of Bohemia’s successor and heir-elect to the Empire (he was to succeed Louis the Bavarian in г 349), Charles IV, decreed its incorporation into the kingdom of Bohemia. He even contemplated the incorporation of the duchies of Plock and Masovia, by virtue of the claims he had inherited from the Vaclavs and his father. With only faltering support from Touis of Hungary and with a storm brewing in the south-east, Casimir resigned himself. By the treaty of Namyslow (Namslau) of 22 November 1348, he abandoned his claims to the Silesian principalities. There was some consolation in the north-east, where in 1 355, Duke Ziemowit III (1341-70), who succeeded in reuniting (albeit briefly) most of the Masovian lands, acknowledged Casimir’s overlordship. He stipulated, however, that the preservation of the relationship after Casimir’s death was contingent on the king’s siring a legitimate male heir.

The troubled situation in the south-east, in the lands of Rus’, helps explain Casimir’s retreat in the west. After the reign of Yaroslav I the Wise (1019-54), the once-great principality of Kiev had undergone its own dynastic fragmentation. The Mongol onslaughts of 1237-40 had savaged these lands far more viciously than Poland. The successor-states of Kievan Rus’ were largely reduced to tributaries of the Golden Horde, established in the Eurasian steppes. The continued raids of the Mongols, or Tatars as they were widely known, carried them periodically into Polish territory. In Г340, Boleslaw-Iurii, the childless ruler of the two westernmost principalities of Halych and Vladimir, and a scion of the Masovian Piasts, was poisoned by his leading boyar-advisers, thoroughly alienated by his open contempt for them and his over-enthusiastic support for Roman Catholicism.

No credible claimant to Halvch-Vladimir emerged from among the other Rus’ princes. Casimir seized the moment. These fertile Rus’ principalities, straddling the great east-west overland trade route front Germany to the Black Sea, offered pleasing prospects of

Borders of Poland Borders of Polish fiefs Territory of the Teutonic Knights

Baltic Sea

enriching both the nobility of southern Poland and the merchants of Krakow. They could serve as a buffer zone against Tatar raids. They offered some compensation for the lands renounced in the west and north. They also aroused the appetite of Lithuania and the Hungarian Angevins. If Casimir did not annex them, others would. His invasion of iC$40 may have been prompted by the very real fear that the Tatars would impose their direct rule in the Tegnum Galiciae et Lodomeriae’, the ‘kingdom of Halych and Vladimir’.