The kingdom of Poland and the grand duchy of Lithuania, ′′ population in fifteenth-century Poland, while the same was happening in the grand duchy of Lithuania, especially in her north-western territories. Information on climatic fluctuations in this part of Europe at that time is so sparse that we may have to rely upon general European weather conditions in the fourteenth and fifteenth centuries, supplemented by the data of dendro- chronology made available from excavations in Rus′. As we know from many places in Europe, the thirteenth century and the first half of the fourteenth underwent some cooling of the climate compared with the favourable condi- tions of preceding centuries. The probable improvement at the end of the century appears to have been only temporary; the fifteenth century again expe- rienced severe climatic conditions, although these were much less harsh than the little ice age which struck from well into the seventeenth century. Various types of weather and regional variation certainly afflicted a wide band of central and eastern European territory. From the itinerary of Wl-adysl-aw II Jagiel--lo (Jogaila), king of Poland and grand duke of Lithuania, we may deduce that winter began early in November when the king drove in his sled for his progress around Lithuania which would last several months. There were still hoar frosts at the end of May and the king fell victim to one of these. Casimir III (the Great) had no male heir, and so the royal line of Piast died with him in . 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 Sl-upsk (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 Sl-upsk. In this regard the terms of Casimir’s will were soon undermined and the duke of Sl-upsk sought compensation for being passed over, accepting the duchies of Dobrzyn´ and Bydgoszcz. The late king’s kinsman, Wl-adysl-aw 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 , another regency consisting of five nobles from Little Poland (Polonia Minor) led by Zawisza, bishop of Cracow, took over. Rus′ of Halicz, Cambridge Histories Online © Cambridge University Press, 2008 which had been annexed to the Polish crown by Casimir III, was ruled by Duke Wl-adysl-aw 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 he granted all the nobility and gentry of the kingdom a charter at Koˇsice 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 – 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 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 nego- tiations 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 . The controlling oligarchs consulted the opposition in Great Poland which was itself divided by the inter- necine 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 fiancé, 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. ′ The Lithuanian state, which developed as a monarchy in the thirteenth century, had been consolidated by Grand Duke Gediminas (c. –), and was to reach the peak of its political power as an independent state in the second half Cambridge Histories Online © Cambridge University Press, 2008 The kingdom of Poland and the grand duchy of Lithuania, ′′ of the fourteenth century. Under the government of the sons of Gediminas, Grand Duke Algirdas and his ally, Prince Kestutis of Trakai, Lithuanian rulers continued to defend their lands against the attacks of the Teutonic Order, which was harrying the western borders of Lithuania in order to unite its lands in Prussia with the Letto-Estonian territories held by the Livonian branch of the Order. While Lithuania was defending its northern and western borders from Catholic crusaders, it took over a wide expanse of territory which stretched from its own original ethnic domains in Aukˇstatija (Upper Lithuania) and Zˇ emaitija (Lower, that is north-western, Lithuania) towards what became known later as Belorussia and Ukraine, as far as Smolensk, Briansk and the Black Sea steppes. Military successes strengthened the despotic authority of the grand duke. Whilst the Lithuanians, members of the Baltic family of Indo- European peoples, resisted Christianity despite repeated attempts to convert them to it, the Rus′ian population inhabiting the greater part of Lithuanian- controlled territory (not ethnic Lithuania but western Rus′) had been Christians of the eastern rite for several centuries. In the fourteenth century the Lithuanian state used Rus′ian written culture in the ruler’s chancery, but in order to preserve its political identity the Lithuanian nobility remained unwill- ing to convert to eastern Christianity, even though such a prospect was consid- ered. Jogaila (Jagiel--lo), son of Algirdas, became grand duke in . Five years later he drove his uncle, Kestutis, from his domain and established himself as sole head of the grand duchy, taking power into his own hands. His first act was to seek an understanding with the Teutonic Order with which he concluded peace in at the unacceptable price of the surrender of Zˇ emaitija. His second course of action was to effect a rapprochement with Moscow. In Jogaila sought a Muscovite alliance, arranged his marriage to the daughter of Dmitry Ivanovich Donskoi, and undertook to receive baptism in the eastern rite. However, these plans came to nought when a third way was offered him by the Polish nobility. This would involve Jogaila’s baptism in the Latin rite, his marriage to Queen Jadwiga and his coronation as king of Poland. Before Lithuania’s eyes spread the prospect of weakening the pressure from the Teutonic Order, initiating joint Lithuano-Polish efforts against the Tatars, and settling the disputed Lithuanian border in Galician Rus′ which was occupied by Poland. The personal union of the kingdom of Poland and the grand duchy of Lithuania was brought about by the Union of Krevo (). As patrimonial lord of Lithuania, when he became king of Poland Jogaila united his inheri- tance with Poland by the terms of this act. On the one hand the patrimonial and personal character of Jogaila’s power contrasted with the Polish crown’s Cambridge Histories Online © Cambridge University Press, 2008 established autonomy from the person of the king. On the other, Polish nobles who wished to interpret the Union as the annexation of Lithuania to the crown encountered resistance from the grand duke’s kinsmen and counsellors who defended the separateness of the Lithuanian state. Jogaila accepted baptism in the Latin rite in Cracow, taking the name of Wl-adysl-aw. As a young man of twenty-three or twenty-four, he married Jadwiga in when she was thirteen. The royal couple henceforth acted together in the most important political affairs. Jadwiga was a figure of uncom- mon beauty and education, a person of deep religious sentiment who was endowed with diplomatic talents that became apparent over the years. She died giving birth to her only daughter in . Wl-adysl-aw II Jagiel--lo came to Cracow with the experience of government gained by his dynasty over several genera- tions and, above all, with personal skills tested in politics and war.