Belarus was long referred to as White Russia because the name "Belarus" translates directly as "White Rus." "Rus" is an antiquated term for pre-modern Russia. In English, the term "White Russia" is considered archaic and is no longer in use. However, many other languages continue to use a direct translation of "White Russia" to reference Belarus.
The term "White Russia" is traceable to the 14th century, but the provenance of the name is unknown. There are several theories, including the idea that "White Rus" refers to the parts of Russia that were never conquered by the Tatars or Mongols.
Belarus was formerly part of the Soviet Union, and it is an independent nation today. Some Belarusians consider the term "White Russia" to be offensive because it creates a verbal link with Russia instead of establishing Belarus as having a separate national identity.
Additionally, it's important to remember that the land borders of Belarus have changed significantly over the years and were last re-established during World War II. Older texts that reference "White Russia" may actually be referring to former parts of Belarus that are no longer included within its borders and are now part of Lithuania, Latvia, Ukraine or Poland.