Ryazan Governorate
Kravkov was born 31 May 1893 in Ryazan in the family of Vasily Pavlovich Kravkov (1859–1920), an army medical officer. At the time of his birth his father held a rank of a Court Councilor (VII grade of the Table of Ranks) and served as a senior physician in the 137th "Nezhinsky" Infantry Regiment based in Ryazan. The future scientist's mother, Elena Alexeyevna, née Lukina (1870 – c. 1922) came of a family of hereditary gentry in the Ryazan Governorate.