The Kingdom of Hungary came into existence in Central Europe when Stephen I, Grand Prince of the Hungarians, was crowned king in 1000 or 1001. He reinforced central authority and forced his subjects to accept Christianity. Although all written sources emphasize only the role played by German and Italian knights and clerics in the process, a significant part of the Hungarian vocabulary for agriculture, religion, and state matters was taken from Slavic languages. Civil wars and pagan uprisings, along with attempts by the Holy Roman emperors to expand their authority over Hungary, jeopardized the new monarchy. The monarchy stabilized during the reigns of Ladislaus I (1077–1095) and Coloman (1095–1116). These rulers occupied Croatia and Dalmatia with the support of a part of the local population. Both realms retained their autonomous position. The successors of Ladislaus and Coloman—especially Béla II (1131–1141), Béla III (1176–1196), Andrew II (1205–1235), and Béla IV (1235–1270)—continued this policy of expansion towards the Balkan Peninsula and the lands east of the Carpathian Mountains, transforming their kingdom into one of the major powers of medieval Europe.

The Hungarian invasions of Europe took place in the 9th and 10th centuries, the period of transition in the history of Europe in the Early Middle Ages, when the territory of the former Carolingian Empire was threatened by invasion from multiple hostile forces, the Magyars (Hungarians) from the east, the Viking expansion from the north, and the Arabs from the south.