Jan was owner of Melsztyn and Książ estates.
He served as Łowczy of Kraków since 1339, castellan of Wojnice since 1345, voivode of the Sandomierz Voivodeship since 1361 and castellan of Kraków since 1360 or 1366.
[1] His granddaughter Elizabeth Granowska (born to his daughter, Jadwiga) became Queen consort of Poland.
During his reign he sponsored various architectural projects; in Kazimierz, for instance, he donated 300 pounds of silver in order to finish the choir of St. Catharine's Church.
[2][3] This biography of a Polish noble is a stub.