The Kingdom of Hungary came into being 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. Civil wars, pagan uprisings and the Holy Roman Emperors' unsuccessful attempts to expand their authority over Hungary jeopardized the new monarchy. Its position stabilized under Ladislaus I (1077–1095) and Coloman (1095–1116). Following the succession crisis in Croatia as a result of their campaign the Kingdom of Croatia entered a personal union with the Kingdom of Hungary in 1102.

Rich in uncultivated lands and in silver, gold, and salt deposits, the kingdom became a preferred target of the continuous immigration of mainly German, Italian and French colonists. Situated at the crossroads of international trade routes, Hungary was affected by several cultural trends. Romanesque, Gothic and Renaissance buildings, and literary works written in Latin prove the predominantly Roman Catholic character of the culture of the Kingdom, but Orthodox, and even non-Christian ethnic minority communities also existed. Latin was the language of legislation, administration and judiciary, but "linguistic pluralism" contributed to the survival of a number of tongues, including a great variety of Slavic dialects.

The predominance of royal estates initially ensured the sovereign's preeminent position, but the alienation of royal lands gave rise to the emergence of a self-conscious group of lesser landholders. They forced Andrew II to issue his Golden Bull of 1222, "one of first examples of constitutional limits being placed on the powers of a European monarch". The kingdom received a major blow from the Mongol invasion of 1241–1242. Thereafter Cuman and Jassic groups were settled in the central lowlands and colonists arrived from Moravia, Poland and other nearby countries.