Alexander Chernichev was born into a prominent Russian noble family. He took part in the 1805 - 1807 campaigns distinguishing himself at Austerlitz and Friedland, before being dispatched on diplomatic missions to France in 1808. He combined a sense of superiority in his own abilities, flourishing in society, with the qualities of an excellent military commander. He also dabbled in politics. It was while in Paris that Chernichev (aged only 22) developed a rapport with Napoleon, and passed on personal messages from Tsar Alexander I. He served as Russian observer in the French army during the Austrian campaign of 1809 and was present at Essling and Wagram. From 1810, in the build up to the 1812 campaign, Chernichev gathered useful intelligence in Paris on French military plans. Together with Karl von Nesselrode, he ran Russian espionage operations in Paris. He obtained many secret documents on Napoleon's preparations against Russia by infiltrating the French Ministry of War. He was obliged to return to Russia after his undercover operations were discovered by the French secret police. He was a key component in the 1812 campaign, serving with Alexander, Kutuzov and Chichagov. He commanded a cavalry detachment from November to December 1812, engaging in the pursuit of Napoleon's retreating army. He then became a major general and adjutant general on 4 December 1812. Chernichev distinguished himself at Marienwerder, Berlin in 1813, for which he was decorated with the Order of St George, 3rd class. He also fought at Luneburg and Kassel, along with conducting his famous cavalry raid into Westphalia. He also commanded a cavalry detachment during the Hundred Days. Chernichev's career continued to flourish after the Napoleonic Wars. He was given the title count of the Russian Empire on 3 September 1826, and was appointed to the Senate in 1827, before rising to becoming general of cavalry later that year. He then served as Minster of War from 1832-1852. On 3 September 1849 he was given the title his highness the prince. In 1856 Chernichev was relieved of his positions as a result of poor health, and died the following year on 20 June 1857.
Alexander Mikaberidze, The Russian Officer Corps in the Revolutionary and Napoleonic Wars, 1792-1815, New York: Savas Beatie, 2005, pp. 58-59 Dominic Lieven, Russia against Napoleon, London: Penguin Books, 2009