It was suspected by Figes that "Lenin" was derived from the river Lena located in Siberia, as Lenin was exiled there when he first started using the pseudonym. Stalin had a variety of nicknames, but used this one most commonly, which translates roughly to "man of steel". Both nicknames were used in order to evade the Tsarist gendarme (in the early 1900's the communist movement was illegal and underground, and pseudonyms were very common as a means of protecting one's identity).