John of Leiden (Dutch: Jan van Leiden; also Jan Beukelsz, Jan Beukelszoon, John Bockold, John Bockelson; February 2, 1509 – January 22, 1536) was an Anabaptist leader from Leiden, in the Holy Roman Empire's County of Holland.
In 1533 he moved to Münster, the capital city of the Holy Roman Empire's Prince-Bishopric of Münster, where he became an influential prophet and a leader of the Münster Rebellion.
He turned Münster, the city, into a millenarian Anabaptist theocracy, and proclaimed himself "king of the New Jerusalem" in 1534.
In 1535, the insurrection was suppressed after a siege of the fortified city, and John was captured, tortured and executed.