Durova cut her hair, donned Cossack clothing, and fled her family to enlist in a Russian cavalry regiment under a male identity, beginning her secret military career.
In September 1806, Nadezhda Durova made the momentous decision to abandon her unhappy marriage and stifling domestic life in Sarapul to pursue the military calling she had craved since childhood. Disguising herself in Cossack male attire and cutting off her hair, she left her family home and attached herself to a passing Cossack regiment, eventually enlisting in the Polish Horse Regiment (Konnopolski Uhlan Regiment) under the assumed name Aleksandr Vasilyevich Sokolov, later also using the name Alexandr Alexandrov.
This act was extraordinarily transgressive for the period: women were legally and socially forbidden from military service, and impersonating a man to enlist carried severe risk of exposure, disgrace, or punishment. Durova's deception required not only physical bravery but constant vigilance to maintain her disguise among fellow soldiers in barracks, on campaign, and in combat.
Her flight marks the true beginning of her decade-long military career, during which she fought against Napoleon's Grand Armée in campaigns across Prussia, Poland, and Russia. It was a foundational act of self-determination that allowed her to become, by most historical accounts, the first Russian woman to serve for an extended period as a combat soldier and officer in the regular army, and it set in motion the events that would eventually bring her to the attention of Tsar Alexander I himself.