Piotrków 1540 Deputies demands presented to the king.

The sejm was called by king Sigismund I on 11 September 1539 to be held on 6 January 1540 in Piotrków. The pre-sejm sejmiks were held in October of 1539. The sejm should have begun on Epiphany (6 January 1540) but in fact the sessions started on 19 January 1540. The main roles during the proceedings were played by king Sigismund II Augustus and queen Bona Sforza. The deputies submitted to the king a list of demands: appointing the vacant seat of hetman office, closing the Prussian mints and changing laws on sentencing for the lése majesté crime. The king was also reminded about the inviolability of Nihil novi act, followed by demands to make the clergy share the burden of national defence. The sejm finished proceedings on 19 March 1540.

See: Ustawodawstwo zob. Volumina Constitutionum, T. 1, cz. 2, Design and layout prepared by W. Uruszczak, S. Grodziski, Irena Dwornicka, Warszawa 2000, s. 217-233.. W. Uruszczak, Sejm walny koronny w latach 1506-1540 [Crown Great Sejm in 1506 - 1540], Warszawa 1980. Z. Wojciechowski, Zygmunt Stary [Sigismund I the Old], Warszawa 1946A. A. Dembińska, Zygmunt I. Zarys dziejów wewnętrzno-politycznych w latach 1540-1548 [Sigismund I. Outlines of the inner-political history in period of 1540-1548 ], Poznań 1948.