Sergei m
Russian: from the old Roman family name Sergius, which is of uncertain, though probably Etruscan, origin. (It was borne, for example, by the conspirator denounced by Cicero, Lucius Sergius Catilina.) St Sergius of Radonezh (c.1314–92) is one of the most famous of all Russian saints, hence the great popularity of the name.
Pet form: Seryozha.
First names dictionary. 2012.