With the beginning of V century to present polish lands came tribes of Slavs. The most important of them were Polanie, Wislanie, Pomorzanie and the Mazovians. Slavs had had their own religion and beliefes, they were living in small societes, reigned by conference of the oldest members of society. Development of Poland started in Wielkopolska land, inhabited by Polan's tribe. Head of the tribe, Mieszko I conquered other tribes and managed create base for a new country, he married chech's princess and was baptized. Unfortunately german neighbour was interested in conquering eastern Europe, soon Mieszko had to fight with german earl and defeated him under battle in Cedynia. After Mieszko came his son Boleslaw, young and ambicious prince. period of his authority was full of new conquests on the east and west from polish borders. In 1025 Boleslaw was crowned. In XIII century Polan, as most of medieval countries, was divided in small duches. In that time came in Poland the Teutonic Order with mission to subordinate northern lands of Poland and also create their own country. Teutonics incorporated many polish lands till kujaw's prince Wladyslaw Lokietek resisted. He unified again the country an disallow teutonic dangerous. After Lokietek, the power was in hand of his only son Kazimierz, who continued father's politics and left in polish memory as a king who modernized Poland. Kazimierz was the last Piast and didn't have son, this way polish crown went to his sister's son, king of Hungary – Ludwik Andegawenski and after his death, polish nobiles chose daughter of Ludwik, young Jadwiga. In 1386 Jadwiga married lithuania's prince Jagiello. It was beginning of jagiellon's dynasty on polish throne. In 1402 and 1413 were signed unions with Great Lithuanian Duchy, it was alliance against Teutonic Order. After that fact, Polish Kingdom was one of the biggest and strongest in Europe. In changed situation Poland defeated the Order twice , once in Grunwald, one of the biggest battles of medieval Europe and other near Koronowo. The war was finished in treaty in Torun. However, Teutonic Order didn't give up and in 1454 new war broke out, this time lasted 13 years. Peace was signed in 1466 in Torun. Poland won and regained lands, lost before.