Stibor of Stiboricz (Hungarian: Stiborici Stibor), (cca. 1348 – February 1414), also Stibor, was an aristocrat, of Polish origin, in the Kingdom of Hungary. He was a close friend of King Sigismund of Hungary who appointed him to several offices during his reign. Stibor was the Voivode of Transylvania (1395-1401, 1409-1414). He styled himself styled himself "Lord of the whole Váh", referring to his 10 castles around the river.
Stibor descended from a Polish noble family whose possession were located around Bydgoszcz in Greater Poland; his father was called Mościc. He arrived to the Kingdom of Hungary during the reign of King Louis I who was also King of Poland (1370-1382). Following the king's death (10 September 1382, the Dowager Queen Elisabeth, who governed the two kingdoms in the name of his daughters, made Stibor the governor of Kuyavia and Leczyca in Poland in 1383. Around this time, Stibor became the close friend of Margrave Sigismund of Brandenburg (the future king and emperor), the fiancé of Queen Mary of Hungary, who had been living in the Hungarian court since 1379.
However, Sigismund could seize the government of Hungary only when the queen and her mother were captured by some rebellious barons (25 July 1386) and appointed Stibor to his Master of the Court. Following his coronation (31 March 1387), King Sigismund entrusted Stibor with the government of Galicia (a province under the supremacy of the kings of Hungary at that time), because the Hungarian "prelates and barons" had persuaded him to promise that he would not employ foreigners in his household. Nevertheless, King Sigmond granted Stibor Bolondóc (1388) and Ugróc (1389) Castles (today Beckovský hrad and Uhrovec, respectively, in Slovakia).
Stibor was granted the ius indigenatus (the right to hold offices) and became the head (ispán) of the Counties Pozsony (1389) and Trencsén and Nyitra (1392). In 1392, Stibor was granted the possession of Csejte and Holics (today Čachtice and Holíč in Slovakia); and he received Berencs, Detrekő, Éleskő, Jókő and Korlátkő Castles in 1394 (today Branč, Plaveč, Ostrý Kameň, Dobrá Voda and Korlátka, respectively, in Slovakia).
In 1395, a foreign delegate mentioned that Stibor and the Archbishop John Kanizsai of Esztergom were the king's most influential advisors.[1]