Jan Zoul was formerly in the service of Wenceslaus IV of Bohemia, before joining the retinue of Prokop of Moravia.[1] At the end of the 14th-century, the nobility rebelled and a coalition of lords was formed against Wenceslaus. Jan and his father, Mikeš Zoul of Ostředek, took advantage of the disorder and seized the castle Čejchanov [cs] near Chocerady. From there, they set out on raids throughout the Benešov region, acting with other robber knights such as Hynek the Dry Devil.[2]
Jan fell out of favor with King Wenceslaus. He was briefly imprisoned by his royally-allied neighbor, Wenceslaus of Dubá, at Karlštejn. However, Jan was pardoned. The neighbors continued to war. In 1403, Jan seized Wenceslaus' castle Stará Dubá [cs]. In doing so, he was declared a land pest and was targeted by royal forces.[3]
In 1404, King Wenceslaus sent a retaliatory army against Jan lead by Archbishop Zbyněk Zajíc of Hazmburk, who recaptured Čejchanov as well as Stará Dubá. Jan, his father, and 50 members[1] of their gang were executed by hanging in Prague on 13 July 1404. His body remained in the gallows for seven years before he was buried at St. Stephen's Church, Prague.[4][5]
After his death, King Wenceslaus confiscated Jan's properties and redistributed them amongst his supporters.[1]