information:highlighting, structural:summarization, linguistic:paraphrasing
Last years (1266–70)

The "nobles of all Hungary, who are called servientes regis " from both the senior and the junior king's domains assembled in Esztergom in 1267. Upon their request, Béla and Stephen jointly confirmed their privileges, which had first been spelled out in the Golden Bull of 1222, before 7 September. Shortly after the meeting, Béla assigned four noblemen from each county with the task of revising property rights in Transdanubia.

King Stephen Uroš I of Serbia invaded the Banate of Macsó, a region under the rule of Béla's widowed daughter, Anna. A royal army soon routed the invaders and captured Stephen Uroš. The Serbian monarch was forced to pay ransom before being released.

Béla's favorite son, also named Béla, died in the summer of 1269. On 18 January 1270 the King's youngest daughter, the saintly Margaret, also died. King Béla too soon fell terminally ill. On his deathbed, he asked his grandson-in-law King Ottokar II of Bohemia to assist his wife, daughter and partisans in case they were forced to leave Hungary by his son. Béla died on Rabbits' Island on 3 May 1270. Dying at 63, he exceeded in age most members of the House of Árpád. He was buried in the church of the Franciscans in Esztergom, but Archbishop Philip of Esztergom had his corpse transferred to the Esztergom Cathedral. The Minorites only succeeded in regaining Béla's remains after a long lawsuit.

King Béla IV of Hungary left to his son, to Stephen, a prosperous, a rebuilt, a fortified kingdom in 28 years. Béla successfully concluded the alliance between the houses of Árpád and Anjou with a mutual marriage contract. In the last year of his life, in December 1269, Abbot of Monte Cassino Bernhard Ayglerius visited Hungary as the envoy of King Charles I of Anjou. He reported enthusiastically to his lord, the foreign, impartial contemporary envoy saw Béla's court as follows:

"The Hungarian royal house has incredible power, its military forces are so large that nobody in the East and the North dares even budge if the triumphant and glorious king mobilizes his army. Most of the countries and princes of the North and East belong to his empire by kinship or conquest."