Baron Yrjö Sakari Yrjö-Koskinen was a friherre, senator, professor, historian, politician and the chairman of the Finnish Party after Johan Vilhelm Snellman. He was a central figure in the fennoman movement. His original name was Georg Zakarias Forsman and his family from his father's side originated from Sweden. He later fennicized his name to Yrjö Sakari Yrjö-Koskinen. He was the husband of Finland's first female author, Theodolinda Hahnsson.