Casimir III (the Great) had no male heir, and so the royal line of Piast died with him in 1370. He provided for the transfer of the Polish crown after his death to his nephew, Louis of Anjou, king of Hungary. However, in his will he sought to secure the position of his grandson, Casimir of Slupsk (in Pomerania), by granting him significant territorial bequests, so that he might eventually succeed Louis, who also had only daughters to succeed him. Louis of Hungary did not mount the throne without incurring the opposition of the nobles of Great Poland (Polonia Maior) and Casimir of Slupsk. In this regard the terms of Casimir’s will were soon undermined and the duke of Slupsk sought compensation for being passed over, accepting the duchies of Dobrzyri and Bydgoszcz. The late king’s kinsman, Wladyslaw the White, the rebel Piast duke of Kujawy, also pressed his claims to the crown.
The Angevin period lasted sixteen years, maintaining the unity of the kingdom of Poland and its administration. Louis strengthened the urban trade networks and the privileges of the towns (including full staple law (ius stapuli) for Cracow, which compelled merchants travelling through that town to put their goods up for sale there). But Louis did not rule Poland personally. His mother, Queen Elizabeth, sister of Casimir III, formed a regency and, after her death in 1380, another regency consisting of five nobles from Little Poland (Polonia Minor) led by Zawisza, bishop of Cracow, took over. Rus' of Halicz, which had been annexed to the Polish crown by Casimir III, was ruled by Duke Wladyslaw of Opole, who attempted to strengthen the mission of the Catholic Church in south-west Rus' and to create a loyal nexus of local and immigrant knights.
The main problem facing the house of Anjou in Poland was how to secure the throne for Louis’s daughters. Louis fostered the good will of the larger cities with his commercial policies. In 1374 he granted all the nobility and gentry of the kingdom a charter at Kosice in Slovakia. This was an act of fundamental importance for the development of noble privileges. The king exonerated nobles from paying the plough tax as the signum summi dominii (service of two grossi per corn field (laneus/lan)). Depending on the quality of the soil, the Ian covered 16—24 hectares cultivated by peasants on noble estates. Henceforth, whenever the king required additional revenues, he could impose them only with the agreement of the nobles. Shortly after this Louis was to grant similar privileges to the clergy.
The Angevin regime, in particular during the regency of the nobles from Little Poland, heightened the nobility’s sense of its political value. After Louis’s death in 1382 the nobility did not fully accept his wishes, refusing to consent to closer union with the Hungarian crown in the person of his daughter, Maria, who had been designated heir to the Polish throne and was engaged to Sigismund of Luxemburg, then margrave of Brandenburg. Two years of negotiations with the queen mother, Elizabeth of Bosnia, led to the accession of the younger daughter, ten-year-old Jadwiga (Hedwig) and her arrival in Cracow, where she was crowned king (rex) in 1384. The controlling oligarchs consulted the opposition in Great Poland which was itself divided by the internecine strife between supporters of the two powerful clans. They also took account of the other pretender to the throne, Siemowit III, duke of Mazovia. The lords of Cracow rejected Jadwiga’s fiance, the newly arrived William of Austria, and drove him out of the capital. They then turned their attention to the new partner in the international game in eastern Europe, the grand duchy of Lithuania. The web of motives which inclined them to turn to Lithuania included collaboration against a common enemy (the Teutonic Order), the need to settle affairs in southern Rus', where Lithuanian and Polish interests came into conflict, and the threat posed to both countries by the Black Sea Tatars.