Among the Pannonians, three brothers, namely Lech, Rus and Czech, were born to Pan, prince of the Pannonians. These three held the three kingdoms of the Lechites, Russians and Czechs. The kingdom of Bohemia was girt by the Erzebirge mountains to the northwest and the Bohemian Forest in the south-west, while in the south-east the White Carpathians separated the dependent mark of Moravia from Slovakia. The thirteenth century brought a second and consolidatory round of 'westernisation' to central Europe. The greatest impact on Hungary and on central Europe as a whole was made by the Tatar invasions. While the western and southern Polish dukes concentrated their attentions primarily on relations with Bohemia and Hungary, the Mazovian Piasts stood further aloof from western alliances. Political developments in central Europe were attended by religious and economic changes which transformed the central kingdoms from passive recipients of alien culture into active members of Latin Christendom and propagators of her values.