 Until the Partitions of Poland, it remained within borders of the Sandomierz Voivodeship, and since 1815, it was part of the Russian-controlled Congress Poland.The town further declined in the 19th century, losing its charter in 1869, after January Uprising.Osiek was destroyed in both world wars, during the Invasion of Poland (September 1939), retreating units of the Polish Army fought here a battle with the Wehrmacht, in which app.