Sokolnicki studied in Warsaw's Corps of Cadets and fought in the Polish–Russian War of 1792 as well as the Kościuszko Uprising of 1794. In 1797 he presented the French Directory with a document entitled "Aperçu sur la Russie". This became known as the so-called "Testament of Peter the Great", which Napoleon Bonaparte used for anti-Russian propaganda purposes in 1812, and has been widely publicised since, although scholars have since established that the document is a forgery.
From 1797 on, Sokolnicki was a member of the Danube Legion and later of the Polish Legions in France under Napoleon. After 1808, he was a general in the army of the Duchy of Warsaw and took part in the Polish–Austrian War, where he was instrumental in defeating the Austrians in two major battles. Sokolnicki then took part in Napoleon's invasion of Russia. After Napoleon's defeat and the Duchy's occupation by Russia, he removed himself from public life and died in an accident in 1816.
- Jerzy Zdrada. "Apollo Korzeniowski's Poland and Muscovy": p. 61
- Neumann, Iver B. "Europe's post-Cold War memory of Russia: cui bono?" in Memory and power in post-war Europe: studies in the presence of the past ed. Jan-Werner Müller. Cambridge University Press, 2002: p. 132
- McNally, Raymond T. "The Origins of Russophobia in France" in American Slavic and East European Review Vol. 17, No. 2 (Apr., 1958): pp. 173-189