Almost at the beginning of his reign we find Venceslas at war with Leopold, Duke of Austria (1231), and the King of Bohemia was on the whole successful in this contest. The Emperor Frederick, then his ally, decreed the ban of the Empire against the Austrian duke (1236).
The friendly relations between the German Emperor and the King of Bohemia did not continue long. Frederick's power was at this time (1237) at its height; he had suppressed all insurrectionary movements in Germany, he had at last defeated the Lombards, and had also united the kingdom of the Two Sicilies with the Empire. Though the contemporary records are very obscure, it seems most probable that Frederick now wished again to render Bohemia as dependent of the Empire as it had at one time been. The nominal cause of the quarrel was Frederick's demand that Venceslas should restore to him certain castles on the frontier of Bohemia and Saxony, which had for some time been in the possession of the sovereigns of Bohemia.[1] Venceslas now reconciled himself with the Pope Gregory IX, and on his request became the ally of Duke Leopold of Austria against the Emperor Frederick. Leopold promised to add the part of the Austrian duchy north of the Danube to the Bohemian kingdom; but failing to keep his promise the friendly relations only lasted a short time. These contests between the German princes were suddenly interrupted by a most unexpected event, the invasion of Eastern and Northern Europe by the Mongols or Tartars, as they were generally, though incorrectly, called.
The Tartars left their original homes in Asia, probably North of China and not far from the region of Lake Baikal, in the first years of the thirteenth century, and, conquering all the countries through which they passed on their march, reached the boundaries of Europe. They easily defeated the disunited Russian princes; and when it became known that they had stormed and burnt the cities of Kief (1240) and Cracow (1241), terror spread all through Europe. Bohemia was directly menaced after the defeat of the Polish and Silesian princes by the Tartars at Liegnitz (1241). Venceslas seems to have behaved with courage and prudence in this emergency. He hastily fortified the
- ↑ The Bohemian frontier, in the direction of Saxony, then extended further to the north-west than at present, reaching as far as the fortress of Königstein.
