Konfederacja (Polish for "confederation") was a temporary association formed by Polish nobility (szlachta), clergy or cities in the Polish-Lithuanian Commonwealth for the attainment of stated aims. Confederations acted in lieu of state authority or to force their demands upon that authority. In the late 13th century, confederations of cities appeared; in the mid-14th century, confederations of nobility, directed against the central authorities (1352, 1439); during interregnums, confederations (essentially vigilance committees) to protect internal order, replace inactive royal courts, and defend the country from external dangers.

In the 17th and 18th centuries, confederations often came out against the king; a confederation unrecognized by him was considered a rebellion (rokosz). Frequent "general confederations" were formed, taking in most or all the provinces (voivodships) of the Commonwealth. The executive branch of a confederation was headed by a marshal, and the confederation's supreme authority was a general council; the confederation's decisions were made by majority vote.

In 1717 and by the May 3rd, 1791, Constitution, adopted by the Four-Year Sejm of 1788-1792 (itself constituted as a confederated sejm so that it could not be disrupted by liberum veto), confederations were proscribed, but in practice this prohibition was not observed. The May 3rd Constitution was overthrown after a year, in mid-1792, by the Targowica confederation formed by Polish magnates backed by Russian Empress Catherine II (the Great) and eventually joined, under extreme duress, by Poland's King Stanislaw August (who in 1764 had become king thanks to his ex-mistress, the Empress Catherine), and by ensuing Russian military intervention leading (to the Confederates' surprise) to the Second Partition of the Polish-Lithuanian Commonwealth in 1793.

See also:

• Confederation
• Confederated sejm
• Sejmik
• Liberum veto
• May Constitution of Poland (adopted May 3rd, 1791)
• Targowica confederation
• Nobles' Democracy