Béla fought with his younger brother, Géza, whom he held in captivity for more than a decade. Taking advantage of the internal conflicts in the Byzantine Empire after Emperor Manuel's death, Béla reoccupied Croatia, Dalmatia and Sirmium between 1180 and 1181. He occupied the Principality of Halych in 1188, but it was lost within two years.

Béla promoted the use of written records during his reign. This emergence evidences the employment of an educated staff. Indeed, students from the kingdom studied at the universities of Paris, Oxford, Bologna, and Padua from the 1150s. Aspects of 12th-century French culture could also be detected in Béla's kingdom. His palace at Esztergom was built in the early Gothic style. According to the consensual scholarly view, "Master P", the author of the Gesta Hungarorum, a chronicle on the Hungarian "land-taking", was Béla's notary. The earliest text written in Hungarian, known as Funeral Sermon and Prayer, was preserved in the late 12th-century Pray Codex. Hungarian chronicles from the 14th century even state that he was responsible for the establishment of the Royal Chancery.