BELA IV. (1206-127o), king of Hungary, was the son of Andrew II., whom he succeeded in During his father's life time he colonized and christianized Transylvania. The salient event of Bela's reign was the terrible Tatar invasion which re duced three-quarters of Hungary to ashes. The terror of their name had long preceded them, and Bela, in 1235 or 1236, sent the Dominican monk Julian, by way of Constantinople, to Russia, to collect information about them from the "ancient Magyars" set tled in the country east of the Volga. He returned to Hun gary with the tidings that the Tatars contemplated the immediate conquest of Europe. Bela appealed to the pope, the duke of Austria and the emperor for assistance ; but in February and March 1241 the Tatars burst through the Carpathian passes; in April Bela himself, after a gallant stand, was routed on the banks of the Sajo and fled to the islands of Dalmatia; and for the next twelve months the kingdom of Hungary was merely a geographical expression. The last 28 years of Bela's reign were mainly devoted to the reconstruction of his realm, which he accomplished with a single-minded thoroughness which has covered his name with glory. (See HUNGARY : History.) Perhaps the most difficult part of his task was the recovery of the western portions of the kingdom (which had suffered least) from the hands of Frederick of Austria, who had seized them as the price of assistance which had been promised but never given. Bela crossed the Leitha on June 15, 1246, and routed Frederick, who was killed in the battle. With him was extinguished the male line of the house of Babenberg. In the south Bela was obliged, in 1243, to cede to Venice, Zara, a perpetual apple of discord be tween the two states ; but he kept his hold upon Spalato and his other Dalmatian possessions, and his wise policy of religious toler ance in Bosnia enabled Hungary to rule that province peaceably for many years. The new Serb kingdom of the Nemanides, on the other hand, gave him much trouble and was the occasion of many bloody wars. In 1261 the Tatars under Nogai Khan invaded Hungary for the second time, but were defeated by Bela. For a time Bela was equally fortunate in the north-west, where the ambitious and enterprising Premyslidae had erected a new Bohe mian empire which absorbed the territories of the old Babenber gers and was very menacing to Hungary. With Ottakar II. in particular, Bela was almost constantly at war for the possession of Styria, which ultimately fell to the Bohemians. In his later years his son Stephen compelled him to divide the kingdom with him, the younger prince setting up a capital of his own at Saro spatak. Bela died on May 3, 1270, in his sixty-fourth year. He married, while still crown prince, Maria, daughter of the Nicaean emperor, Theodore Lascaris. She bore him, besides his two sons Stephen and Bela, seven daughters, of whom St. Margaret was the most famous.
No special monograph for the whole reign exists. For the Tatar invasion see the contemporary Rogerius, Epistolae super destructione Regni Hungariae per Tartaros facta (1885). A vivid but somewhat chauvinistic history of Bela's reign will be found in Acsady's History of the Hungarian Realm (Hung.), i. 2 (19o3). (R. N. B.)