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.