Sejm in Piotrków in early spring. 1509.
The sejm was convened in November 1508 to Piotrków. The pre-sejm sejmiks took place at the turn of February 1509. The sejm sessions lasted from 11 March to 16 April 1509. The proceedings benefited with numerous documents and law acts.
See: Z. Wojciechowski, Zygmunt Stary [Sigismund I the Old], Warszawa 1946. W. Uruszczak, Sejm walny koronny w latach 1506-1540 [Crown Great Sejm in 1506 - 1540], Warszawa 1980. Ustawodawstwo zob. Volumina Constitutionum, T. 1, cz. 1, Design and layout prepared by S. Grodziski, I. Dwornicka, W. Uruszczak, Warszawa 1996, s. 212-219.