Russian officers: Nikolai Petrovich of Oldenburg
Prince Nikolai Petrovich of Oldenburg (27 April [9 May] 1840, Saint Petersburg – 8  in January 1886, Geneva) – His Highness Lieutenant General of the Russian army, a member of the Imperial House, the grandson of Grand Duchess Catherine Pavlovna. At birth, baptized in the evangelical faith, but at the court of his name in the Russian tradition: by name and patronymic.
Was educated at home, preparing for military service. From birth enrolled ensign Life Guards Regiment. January 25, 1856 began his military service with the rank of lieutenant in the Life Guards cavalry squadron pioneer. In August 1861 in the rank of colonel appointed its commander.
June 22, 1863 dismissed “due to illness” (in fact, the Prince of Oldenburg made a morganatic marriage, has displeased emperor). Three years later, thanks to the intercession of the Grand Duke Nicholas, who was married to his sister Alexandra, Nikolai Petrovich was allowed to return to military service.
Appointed a colonel in the 5th Hussars Regiment of Alexandria. On 11 February 1867 the commander of the 1st Battalion of the regiment. On February 11, 1868 – the commander of the 13th Lancers Regiment of Vladimir. In 1872 he was promoted to major general, and in 1883 – to lieutenant general.
Recent years, Nikolai spent on the island of Madeira, where it was treated for tuberculosis. Died 8 (20) January 1886 at the age of forty-six years in Geneva.