Lithuania was established in the beginning of the 13th century, when Prince Mindaugas united several Lithuanian tribes. Mindaugas was one of the last European rulers to abandon the old pagan religion and to be baptised into the Christian faith. In just a couple of hundred years, Lithuania became an influential and powerful country in the east of Europe. Lithuania expanded to the south and to the east during wars against the Russians, the Teutonic Knights and the Mongolians. The costs of these wars were largely paid by the Lithuanian peasants. As the taxes were raised, the noblemen became richer and richer and the peasants more and more dependant on the aristocracy.
Despite its powerful position, Lithuania felt threatened by its neighbouring countries. By forming a union with Poland in 1385, the country grew and gained more power. In 1386, the Polish Queen married the Lithuanian Grand Duke. He became the new ruler of this vast kingdom under the name Vladislav II.