What was the king whose mistress was Elżbieta Branicka criticized of as the last king of the Commonwealth?
Elżbieta Branicka: Elżbieta Branicka (c.1734-1800) was a Polish noble lady, political plotter, mistress of King Stanisław August Poniatowski. Stanisław August Poniatowski: Stanisław II Augustus (also Stanisław August Poniatowski; born Stanisław Antoni Poniatowski; 17 January 1732 – 12 February 1798) was the last King of Poland, Grand Duke of Lithuania and the last monarch of the united Polish–Lithuanian Commonwealth (1764–95). Stanisław August Poniatowski:  He is criticized primarily for his failure to stand against the partitions, and thus to prevent the destruction of Poland.
failure to stand against the partitions, and thus to prevent the destruction of Poland