As examples , for Greeks , Constantine XI Palaiologos and Kolokotronis ; and for Serbs , Miloš Obilić and Tzar Lazar ; for Montenegrins , Đurađ I Balšić and Ivan Crnojević ; for Albanians , George Kastrioti Skanderbeg ; for ethnic Macedonians , Nikola Karev for Bulgarians , Vasil Levski , Georgi Sava Rakovski and Hristo Botev and for Croats , Nikola Šubić Zrinjski .