Jan Dekert

He was the mayor of Warsaw (1789–1790), during which period he organized the Black Procession on 2 December 1789 (a march of burghers who delivered a petition to the king).

This was a major step towards the passing of the Free Royal Cities Act enfranchising burghers, as one of the reforms of the Great Sejm and part of the Constitution of the 3rd May, 1791.

[2] In December 1756 Dekert was admitted to the Warsaw "youth" Confraternity of Merchants (warszawska konfraternia kupiecka "młodziańska").

[4] By 1762 he had taken over the cloth store, moved from the "youth" Confraternity of Merchants to the "senior" ("starsza") one, and become a full citizen of Warsaw.

[6] According to Jędruch, he became Alderman (a position usually known in Polish as "radny") of Warsaw in 1769, but this is contradicted by Zienkowska; according to her, it was only in 1776 that he reached the rank of "ławnik" in the magistrate.

[11][12][13] The procession influenced the Great Sejm to create a Commission for the Cities (Deputacja w sprawie miast) tasked with addressing those concerns during the works on the new constitution.

[16] In February 1790, despite his objections, he was pressured by the public opinion into reelection for a second (yearly) term of office as the mayor of Warsaw.

[19][20] He died before the Free Royal Cities Act, enfranchising burghers, was passed in 1791 as one of the reforms of the Great Sejm, next to the Constitution of the 3rd May, 1791.