BELA IV. (1206-1270), king of Hungary, was the son of Andrew II., whom he succeeded in 1235. During his father's lifetime he had greatly distinguished himself by his administration of Transylvania, then a wilderness, which, with incredible patience and energy, he colonized and christianized. He repaired as far as possible the ruinous effects of his father's wastefulness, but on his accession found everything in the utmost confusion, "the great lords," to cite the old chronicler Rogerius (c. 1223-1266), "having so greatly enriched themselves that the king was brought to naught." The whole land was full of violence, the very bishops storming rich monasteries at the head of armed retainers. Bela resolutely put down all disorder. He increased the dignity of the crown by introducing a stricter court etiquette, and its wealth by recovering those of the royal domains which the magnates had appropriated during the troubles of the last reign. The pope, naturally on the side of order, staunchly supported this regenerator of the realm, and in his own brother Coloman, who administered the district of the Drave, Bela also found a loyal and intelligent co-operator. He also largely employed Jews and Ishmaelites,  the financial specialists of the day, whom he rewarded with lands and titles. The salient event of Bela's reign was the terrible Tatar invasion which reduced 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" settled there, possibly the Volgan Bulgarians. He returned to Hungary with the tidings that the Tatars contemplated the immediate conquest of Europe. Bela did his utmost to place his kingdom in a state of defence, and appealed betimes 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 Sajó and fled to the islands of Dalmatia; and for the next twelve months the kingdom of Hungary was merely a geographical expression. The last twenty-eight 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. First Bela solicited the aid of the pope, but was compelled finally to resort to arms, and crossing the Leitha on the 15th of June 1246, routed Frederick, who was seriously wounded and trampled to death by his own horsemen. With him was extinguished the male line of the house of Babenberg. In the south Bela was less successful. In 1243 he was obliged to cede to Venice, Zara, a perpetual apple of discord between the two states; but he kept his hold upon Spalato and his other Dalmatian possessions, and his wise policy of religious tolerance in Bosnia enabled Hungary to rule that province peaceably for many years. The new Servian 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 and lost 50,000 men. Bela reached the apogee of his political greatness in 1264 when, shortly after his crushing defeat of the Servian king, Stephen Urosh, he entertained at his court, at Kalocsa, the ambassadors of the newly restored Greek emperor, of the kings of France, Bulgaria and Bohemia and three Tatar mirzas. For a time Bela was equally fortunate in the north-west, where the ambitious and enterprising Pøemyslidae had erected a new Bohemian empire which absorbed the territories of the old Babenbergers 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. The last years of Bela's life were embittered by the ingratitude of his son Stephen, who rebelled continuously against his father and ultimately compelled him to divide the kingdom with him, the younger prince setting up a capital of his own at Sárospatak, and following a foreign policy directly contrary to that of his father. Bela died on the 3rd of May 1270 in his sixty-fourth year. With the people at large he was popular to the last; his services to his country had been inestimable. He married, while still crown-prince, Maria, daughter of the Nicaean emperor, Theodore Lascaris, whom his own father brought home with him from his crusade. 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 Hungarias per Tartaros facta (Budapest, 1885). A vivid but somewhat chauvinistic history of Bela's reign will be found in Acsády's History of the Hungarian Realm (Hung.), i. 2 (Budapest, 1903).
(R. N. B.)
 Mahommedan itinerant chapmen, from the Volga.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)