The salient event of Bela's reign was the terrible Tatar invasion which reduced three-quarters of Hungary to ashes.
The last twentyeight years of Bela's reign were mainly devoted to the reconstruction of his realm, which he accomplished with a singleminded thoroughness which has covered his name with glory.
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 Sarospatak, and following a foreign policy directly contrary to that of his father.
A vivid but somewhat chauvinistic history of Bela's reign will be found in Acsady's History of the Hungarian Realm (Hung.), i.
Subsequently, however, he married the handsome and promising youth to Agnes of Chatillon, duchess of Antioch, and in 1173 placed him, by force of arms, on the Hungarian throne, first expelling Bela's younger brother Geza, who was supported by the Catholic party.
It was in Bela's reign that the emperor Frederick I., in the spring of 1189, traversed Hungary with ioo,000 crusaders, on which occasion the country was so well policed that no harm was done to it and the inhabitants profited largely from their commerce with the German host.