Grand Duke Peter Nikolaevich of Russia (10 January 1864 – 17 January 1931) was a Russian Grand Duke and a member of the Russian Imperial Family.
Grand Duke Peter Nikolaevich was the second son of Grand Duke Nicholas Nicolaievich the Elder (1831–1891) and Duchess Alexandra of Oldenburg (1838 – 1900).
He was born in Saint Petersburg. As was the custom for Russian Grand Dukes (the title applied to all sons and grandsons of a Russian Emperor), the Grand Duke Peter served in the Russian army as a Lt.-General and Adjutant-General.
On 26 July 1889, he married Princess Milica of Montenegro (1866–1951), daughter of King Nicholas I of Montenegro (1841–1921). The Grand Duke and Duchess had four children:
Princess Marina Petrovna of Russia (1892–1981)
Prince Roman Petrovich of Russia (1896–1978)
Princess Nadejda Petrovna of Russia (1898–1988)
Princess Sofia Petrovna of Russia (3 March 1898 – 3 March 1898); buried in the convent cemetery in Kiev by her grandmother, Grand Duchess Alexandra Petrovna, who was a nun there.
In 1907, his elder brother, Grand Duke Nicholas Nikolaevich, married Grand Duchess Militza’s sister, Princess Anastasia of Montenegro, known as Stana. The two couples were socially very influential at the Russian Imperial Court in the early 20th century. Nicknamed joined “the black peril”, a group interested in the occult. They are credited with introducing first a charlatan mystic named merely Philippe, and then, with graver consequences, Grigori Rasputin (1869–1916) to the Imperial family. Prince Felix Yussupov (1887–1967) — who was their neighbour in Koreiz — once described Znamenka, the Grand Duke and Duchess’s palace, as “the central point of the powers of evil”. This was later to be a widely held belief within the higher echelons of the divided Russian court. The Dowager Empress Marie firmly believed that the couple plotted with Rasputin and others to gain influence and favours through the neurotic Empress Alexandra (1872–1918). However, by 1914, Alexandra herself referred to them as “the black family” and felt herself to be manipulated by them.