With the beginning of the Russian campaign in late June 1812, Emperor Napoleon I launched with his Grande Armée, in a series of envelopment maneuvers of the Russian Imperial armies before him, with the first such maneuver failing before the city of Vilna, virtually without any engagement taking place. Napoleon then launched a second such attempt towards Vitebsk, in a bid to turn the main Russian army under Barclay de Tolly. With French forces moving through different routes in the direction of Vitebsk, a first major engagement took place on 25 July near Ostrowno, 30 kilometers west of Vitebsk, when General Etienne de Nansouty's 1st Cavalry Reserve Corps encountered the forces of Russian General Alexander Ivanovich Ostermann-Tolstoy.