From the time of the introduction of Christianity into Bohemia the history of the country becomes less obscure. The first attempts to introduce Christianity undoubtedly came from Germany. They met with little success, as innate distrust of the Germans naturally rendered the Bohemians unfavourable to a creed which reached them from the realm of their western neighbours. Matters were different when Christianity approached them from Moravia, where its doctrine had been taught by Cyrillus and Methodius--Greek monks from Thessalonica. About the year 873 the Bohemian prince Borivoj was baptized by Methodius, and the Bohemians now rapidly adopted the Christian faith. Of the rulers of Bohemia the most famous at this period was Wenceslas, surnamed the Holy, who in 935 was murdered by his brother Boleslav, and who was afterwards canonized by the Church of Rome. As Wenceslas had been an ally of Germany, his murder resulted in a war with that country, in which, as far as we can judge by the scanty records of the time. Boleslav, the brother and successor of Wenceslas, was on the whole successful. During the reigns of Boleslav and his son, Boleslav II., Bohemia extended its frontiers in several directions. Boleslav II. indeed established his rule not only over Bohemia and Moravia, but also over a large part of Silesia, and over that part of Poland which is now the Austrian province of Galicia. Like most Slavic states at this and even a later period, the great Bohemian empire of Boleslav II. did not endure long. Boleslav III., son of Boleslav II., lost all his foreign possessions to Boleslav the Great, king of Poland. During his reign Bohemia was involved in constant civil war, caused by the dissensions between Boleslav III. and his brothers Jaromir and Ulrick. Though the prince succeeded in expelling his brothers from the country, his cruelty induced the Bohemians to dethrone him and to choose as their ruler the Polish prince Vladivoj. Vladivoj, brother of Boleslav the Great, and son of the Bohemian princess Dubravka (Dobrawa). Vladivoj attempted to strengthen his hold over Bohemia by securing the aid of Germany. He consented not only to continue to pay the tribute which the Germans had already obtained from several previous rulers of Bohemia, but also to become a vassal of the German empire and to receive the German title of duke. This state continued when after the death of Vladivoj the Premyslide dynasty was restored. The Premyslide prince Bretislav I (1037-1055) restored the former power of Bohemia, and again added Moravia, Silesia and a considerable part of Poland to the Bohemian dominions. To obviate the incessant struggles which had endangered the land at every vacancy of the throne, Bretislav, with the consent of the nobles, decreed that the oldest member of the house of Premysl should be the ruler of Bohemia. Bretislav was therefore succeeded first by his eldest son Spitihnev, and then by his second son Vratislav. Vratislav becomes "king".