This site is a collation of descendants of Nathan Relkin. Nathan is, presumably, from Slutsk, which is now part of Belarus, although no documentary evidence for this has been found. His wife was born there and his son reports it as his last residence prior to emigrating, but existing documents show only that Nathan was from Russia.
Slutsk lies south of Minsk and just west-southwest of Babruysk (Bobruisk). This area changed hands often; it has been part of Russia, Germany, Poland, Lithuania as well an independent country at various times in history. At the beginning of the 20th century, when the Relkins emigrated, it was part of the Russian Empire.
The information here comes from various Relkin descendants, both in my line and others.