Source: Motyka, Grzegorz. Zapomnijcie o Giedroyciu: Polacy, Ukraińcy: IPN, 2008
Roman-Taras Yosypovych Shukhevych was a Ukrainian nationalist and a military leader of the nationalist Ukrainian Insurgent Army , which during the Second World War fought against the Soviet Union and to a lesser extent against the Nazi Germany for Ukrainian independence. He collaborated with the Nazis from February 1941 to December 1942 as commanding officer of the Nachtigall Battalion in early 1941, and as a Hauptmann of the German Schutzmannschaft 201 auxiliary police battalion in late 1941 and 1942.Shukhevych was one of the perpetrators of the Galicia-Volhynia massacres of tens of thousands of Polish civilians. It is unclear whether and to what extent Shuchevych was responsible for the massacres of Poles in Volhynia, but he certainly condoned them after some time, and also directed the massacres of Poles in Eastern Galicia. Historian Per Anders Rudling has accused Ukrainian diaspora and Ukrainian academics of "ignoring, glossing over, or outright denying" his role in this and other war crimes. Wikipedia
Source: Motyka, Grzegorz. Zapomnijcie o Giedroyciu: Polacy, Ukraińcy: IPN, 2008