Ruthenia is a geographical region in Eastern Europe that has been also referred to by different names throughout history. One of the synonyms for Ruthenia is Rus, which was used as an alternate term in the Middle Ages. Another synonym is Galicia, a historical and geographical region in modern-day Ukraine and Poland, where Ruthenians lived. The term Carpatho-Ruthenia was also used to describe the area in the early 20th century. Additionally, the term Subcarpathian Rus was adopted for the region during the interwar period. Another term used for Ruthenia is Red Ruthenia, referring to the western part of the region, which became the Kingdom of Galicia and Lodomeria.