As a young man Zubov had flattering prospects of a brilliant military career due to his brother Platon's ascendancy at Catherine II's court.

He was appointed General-Major and sent to assist Suvorov in quelling the Kościuszko Uprising in Poland, where he was said to treat both the Polish noblemen and their wives brazenly and "in the most lowly manner".

During this stay in Poland, he married Princess Marianna Lubomirska (1773-1810), widow of Count Antoni Protazy Potocki, Teodor Lubomirski's adopted granddaughter and lost his left leg in the autumn of 1794 while crossing the Western Bug, as he was wounded by a cannonball.

Zubov started the expedition in a much promising manner, seizing Derbent in Dagestan in April 1796, and Baku by July of the same year.

Zubov's return from his luckless expedition occasioned an ode by Gavrila Derzhavin, meditating on the fleeting nature of fortune and success.