Sviatoslav I of Kiev
Ukrainian Cossacks traditionally have a distinctive facial hair style – long "cossack" moustache was very popular across Ukraine during Middle Ages until modern times. The tradition allegedly dates back at least to the times of prince of Kyevan Rus' Sviatoslav I of Kiev famous for his military campaigns in the east and south. Sviatoslav had distinctive moustache and hair style (oseledets or chupryna) that almost every Ukrainian cossack had centuries after his times (although Svyatoslav had lived in 10th century, while Cossacks appear on the historical scene only since the 15th century).