thumb|right|250px|The swearing in of the [[Tyszowce Confederation in 1655, painting by Walery Eljasz-Radzikowski.]]
A konfederacja (, confederation, confederacy) was an ad hoc association formed by the nobility (szlachta), clergy, and municipalities to pursue their stated aims or act in place of state authority, created in Poland and Lithuania between the 13th and 19th centuries. A konfederacja often took the form of an armed union aimed at redressing perceived abuses or trespasses by some authority, such as the royal authority. These "confederations" acted in place of state authority or to force their demands upon that authority.
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