Who are you, professor Petrova?

The previously unknown facts of the biography of Maria K. Petrova, a student and colleague of academician I.P. Pavlov, are presented. Archival research and analysis of previously inaccessible materials allowed to restore her biography hidden from the public by shedding light on the development of her personality and scientific perspective. Maria spent her early childhood far from St. Petersburg, in a small military garrison in the Caucasus. However, she graduated from high school in the capital of the Russian Empire. The discovered data both shed light on her childhood and youth and provide background information on her parents, spouse, brothers and sisters. This information allows us to reinterpret her decision to get a higher education and practice medicine and reveals the roots of her loyalty to Ivan Pavlov. The article describes Maria Petrova’s character traits, which allowed her to become an outstanding researcher rather than just a mother of a family. Her decision to get a medical degree could not but affect her relationship with her husband, Grigory S. Petrov, from whom she later divorced. Undoubtedly, the new findings will be an impetus for historians of science.