Hungary’s involvement beyond her southern borders, in the Balkan lands, began virtually by accident. It was to last for nearly five-hundred years and then resulted in Hungary’s loss of independence for a further four-hundred. Towards the end of the ill-starred reign of Solomon (1063-74), emperor Michael VII of Byzantium encouraged Hungary’s old enemies to the east, the Pechenegs, to invade Transylvania and southern Hungary. In 1071 they were defeated by the Prince Royal, Géza (later Géza I, 1074-77), who besieged, captured, and occupied the strategic fort of Belgrade in the process. Concluding that a direct confrontation with Géza would be unproductive, the emperor opted for reconciliation, symbolized by the crown Géza accepted from him in 1074 after succeeding Solomon. Fifteen years later, in 1089, King Zvonimir of Croatia died without leaving an heir. His widow, Helen, was the sister of Ladislas I of Hungary, who had succeeded his brother Géza in 1077. Because of this dynastic link, and probably also because Géza’s capture of Belgrade had established Hungary as a power in the region, a delegation of nobles from Spalato (Split) invited Ladislas to accept the Croatian crown, an offer of dynastic aggrandizement which no Árpád could refuse. Ladislas thereupon annexed northern Croatia in 1091 and installed his nephew Álmos as ruler. A by-product of this campaign was the incorporation into the Hungarian kingdom of Slavonia, the region to the northeast of Croatia lying between the Drava and Sava rivers.

From Bryan Cartledge’s The Will to Survive: A History of Hungary, London: Hurst & Company, 2011 (first published in 2006), p. 26.