Ferenc Nádasdy died on 4 January 1604 at the age of 48. Although the exact nature of the illness which led to his death is unknown, it seems to have started in 1601, and initially caused debilitating pain in his legs. From that time, he never fully recovered, and in 1603 became permanently disabled. He had been married to Báthory for 29 years. Before dying, Nádasdy entrusted his heirs and widow to György Thurzó, who would eventually lead the investigation into Báthory's crimes.