What is the origin of the word Russian?

The word "Russian" has several origins, including:

• Proto-Slavic: The word "rus'ka" or "rus'naya" is believed to be the origin of the word "Russian". This word was used by the Slavic peoples in the 6th and 7th centuries to refer to a person from the Rus' land, which was located in the southern part of the former Russian Empire.
• Proto-West Slavic: The word "rus'" is also believed to be the origin of the word "Russian" in Proto-West Slavic, a language spoken by Slavic peoples in the 6th and 7th centuries.
• Old Church Slavonic: The word "rus'" is also believed to be the origin of the word "Russian" in Old Church Slavonic, a language spoken by Slavic peoples in the 8th and 9th centuries.

The word "Russian" first appeared in written sources in the 13th century, and it was used to refer to people from the Russian Empire. The word has since been used to refer to people from all parts of the former Russian Empire, as well as to refer to the language and culture of Russia.