The Hungarian nobility consisted of a privileged group of laymen, most of whom owned inheritable landed property, in the Kingdom of Hungary (including all the Lands of the Crown of Saint Stephen as well) between the 1260s and 1946. Late 12th-century documents used the term "noblemen" in reference to the dignitaries of the royal court and the heads of the counties. Most of these aristocrats were native lords, some even tracing their families' origins back to tribal chiefs who lived at the time of the Hungarian conquest of the Carpathian Basin around 895. Other aristocrats were regarded as newcomers, because their ancestors (mainly German, Italian and French knights) came after the establishment of the kingdom around 1000. The immigrant knights contributed to the introduction of heavy cavalry and the spread of chivalric culture. According to scholarly theories, groups of Slavic or Romanian notabilities of the polities from the period preceding the Hungarian conquest also survived.
Beside the aristocrats, less illustrious individuals held landed property and were obliged to provide military service throughout the kingdom. For instance, a privileged group of armed serfs – the "castle warriors" – held estates in the lands attached to royal castles. Through the integration of the different classes of free and non-free warriors, a new group emerged after a decline in royal power started at the end of the 13th century. They referred to themselves as "royal servants" to emphasize their direct contact to the monarch. They forced Andrew II of Hungary to spell out their liberties (including their exemption of royal taxes) in the Golden Bull of 1222, which became the fundamental document of noble privileges. The royal servants' identification as noblemen was enacted in 1267. The highest royal officials had by that time were mentioned as "barons of the realm". In short time, the counties transformed into the most important institutions of the self-government of noblemen. A decree of 1351 declared the principle of "one and the selfsame liberty" of all noblemen. However, there were groups of privileged landowners – the so-called "conditional nobles" – that did not enjoy all the privileges of "true noblemen"; for instance, they were to render military services in exchange for the estates that they held on their lords' domains. Moreover, significant economic, political and social differences existed between the wealthiest noblemen (who owned castles and dozens of villages and held sway over thousands of peasants) and noblemen who themselves cultivated their tiny plots. The rich landowners employed impoverished noblemen in their households as their familiares. Through their familiares, they could control both the counties and the Diet, or parliament.