of the population received special privileges: the 24 "Saxon" towns formed an autonomous community, independent of Spiš county, and the "nobles with ten lances" were organised into a special autonomous administrative unit ("seat"). In 1412, King Sigismund mortgaged 13 of the "Saxon" towns to King Władysław II of Poland so they de facto belonged to Poland until 1769. From the 1320s, most of the lands of present-day Slovakia were owned by the kings, but prelates and aristocratic families (e.g., the Drugeth, Szentgyörgyi and Szécsényi families) also hold properties on the territory. In December 1385, the future King Sigismund, who was Queen Mary of Hungary's prince consort at that time, mortgaged the territories of present-day Slovakia west of the Váh River to his cousins, the Jobst and Prokop of Moravia; and the former held his territories until 1389, while the latter could maintain his rule over some of the territories until 1405. King Sigismund (1387–1437) granted vast territories to his followers (e.g., to the members of the Cillei, Rozgonyi and Perényi families) during his reign; one of his principal advisers, the Polish Stibor of Stiboricz styled himself "Lord of the whole Váh" referring to his 15 castles around the river. Following the death of King Albert (1439), civil war broke out among the followers of the claimants for the throne. The Dowager Queen Elisabeth hired Czech mercenaries led by Jan Jiskra who captured several towns on the territory of present-day Slovakia (e.g., Kremnica, Levoča and Bardejov) and maintained most of them until 1462 when he surrendered to King Matthias Corvinus. Modern Era Early Modern Period Habsburg and Ottoman administration The Ottoman Empire conquered the central part of the Kingdom of Hungary, and set up several Ottoman provinces there (see Budin Eyalet, Eğri Eyalet, Uyvar Eyalet). Transylvania became an Ottoman protectorate vassal and a base which gave birth to all the anti-Habsburg revolts led by the nobility of the Kingdom of Hungary during the period 1604 to 1711. The remaining part of the former Kingdom of Hungary, which included much of present-day territory of Slovakia (except for the southern central regions), northwestern present-day Hungary, northern Croatia and present-day Burgenland, resisted Ottoman conquest and subsequently became a province of the Habsburg monarchy. It remained to be known as the Kingdom of Hungary, but it is referred to by some modern historians as the "Royal Hungary". Ferdinand I, prince of Austria was elected king