Operation Vistula
Until 1947, 45% of the population of this part of the mountains were Lemkos and Dolinians (both subgroups of Rusyns), 45% Polish Uplanders and 10% Jews. The killing of the Polish General Karol Świerczewski in Jabłonki by the Ukrainian Insurgent Army in 1947 was the direct cause of the replacement of the Lemkos, the so-called Operation Vistula.