Рязанская губерния
Nikolai Kravkov was born a sixth child in the family of a non-commissioned officer Pavel Alexeyevich Kravkov (1826-1910), who served as a senior clerk in the office of the Chief Enlistment Officer of the Ryazan Governorate. According to the family legend, the scientist's mother Evdokia (Avdotia) Ivanovna (1834-1891), before wedding a "Kaluga petty bourgeois", was an illegitimate daughter of Konstantin Kavelin (1818-1885), a famous Russian historian, jurist and sociologist, one of the ideologists of Russian liberalism during the age of the reforms of Alexander II.