Having centralized all the central-eastern territories of Poland in his hands, Casimir turned his gaze to the east, extended his sovereignty over some regions of the Bug, fought successfully against the Baltic and pagan tribe of the Jadvingi, asserted his authority also on the Halicz and became one of the creators of Polish Eastern policy as the power of Kiev was falling apart.
Even more fatal than the threatening and systematic German offensive were for Poland in the following decades the continuous fragmentation of the territories, the exemption of them from the supremacy of Krakow, the constant growth of the power of the aristocracy. Dynastic unity, a vague but still sensitive national consciousness and the fact that Poland, as a whole, continued to be an ecclesiastical province, were for a long time, in the midst of so much disintegration, the only unitary factors.
According to harvardshoes.com, the period of decline lasted a whole century. The history of Poland must be replaced for the century. XIII, the history of the individual territories. Few facts alone, and more for later reflections than for their immediate significance, have an importance for the whole of Poland. First of all, the call by Conrad of Masovian (1226) of the Teutonic Order, which to Christianize pagan Prussia firmly settled in the land of Culmia (Chełmno), founded the stronghold of Toruń (Thorn), and from there moved to the an offensive which, with an evidently somewhat extensive interpretation of the deeds of donation of the Polish duke – but with the consent of the emperor and the pope -, made them masters, in a few decades, of all Prussia up to Niemen. German colonists were promptly introduced into the occupied lands, and the power of the Teutonic Knights grew by drawing new forces from the union with the Order of the Sword-holders, which, having formed in Livonia, began to extend its activity to nearby Samogitia and Lithuania. The serious consequences of Conrad’s rash act only appeared later in all their fullness, but in those years it was aggravated by the almost contemporary detachment from Poland (1227) of eastern Pomerania. At the same time, the Poles, while strenuously defending themselves and appearing for the first time in history as defenders of the West, suffered the ruinous invasion of the Tatars, who, as well as devastating the southern regions, put an end to the great ambition of restoring unity. Polish that the Silesian branch of the Piasti, led first by Henry the Bearded (1228-1238) and then by his son Henry the Pious, who died in the battle of Liegnitz (1241), he had nurtured, and partly already built. Finally, it is worth noting the introduction also in Poland of the reform of the Church which was imposed there thanks above all to the energetic action of the archbishop of Gniezno, Enrico Kietlicz. Indeed, it weakened secular power, but it greatly contributed to raising not only the moral and spiritual level of the clergy, but also, in part at least, of the whole nation. Thus it was that the canonization of Saint Stanislaus (1254), who became the patron saint of the Poles, gave a new impulse to the feeling of national solidarity, and, increasing the prestige of Krakow,
Towards the end of the century these difficulties, instead of diminishing, were still increasing. Against the ephemeral successes of Leszek the Black (1279-1288) in Halicz, and his final victory against the Jadvingi (1282); against the wise administrative reforms of Henry IV the Probus (1288-1290) and the incorporation, by inheritance, of Eastern Pomerania by Przemysław II (1295) who, thanks to the energetic action of Archbishop Świnka, managed to obtain, in Gniezno, not in Krakow, the royal crown (1295), are: the growing Germanization of Silesia (Breslau had already become a predominantly German city); the constant quarrels between the individual members of the dynasty and between them and the magnates; and what is worse the invasion of Krakow by the Bohemian armies of Wenceslaus II (1291), of Sandomierz (1292) and then also of Great Poland (1300). Because Wenceslaus, who thanks to the support of Emperor Albert I had managed to surround. the royal crown of Poland (1300), also obtained a part of Kuyavian, Pomerania and sovereignty over some other territories, he could appear as the first unifier of the Polish lands. But the Poland of Wenceslas, a vassal of the empire, had no national character: the Bohemian prince based his rule on foreign elements – the German bourgeoisie, and Czech employees and soldiers. he could appear as the first unifier of the Polish lands. But the Poland of Wenceslas, a vassal of the empire, had no national character: the Bohemian prince based his rule on foreign elements – the German bourgeoisie, and Czech employees and soldiers. he could appear as the first unifier of the Polish lands. But the Poland of Wenceslas, a vassal of the empire, had no national character: the Bohemian prince based his rule on foreign elements – the German bourgeoisie, and Czech employees and soldiers.