Fersen graduated from the SeaCadet Corps in 1875 and joined the Imperial Russian Navy in 1876. In 1878–80 he served aboard the cruiser Asia with the Russian Pacific Fleet, transferring to the cruiser Afrika from 1880 to 1883. On July 10, 1883, he was posted to Kronstadt. He was promoted to lieutenant on January 1, 1885, and served aboard the gunboatBobr as officer of the watch later that year. He remained on the Bobr on its long distance navigational training voyage to the Far East from 1886 to 1888. From 1889 to 1890 Fersen attended the Russian navy mine warfare school and served in staff posts in the Russian Baltic Fleet from 1890 to 1896. In 1896 he commanded the destroyerVzryv. In 1897–99 he was senior officer aboard the cruiser Afrika. On April 28, 1899 he was promoted to captain 2nd rank and served as naval attaché to the United States from September 1899 to 1902. On October 7, 1902, Fersen was appointed to command the cruiser under the Second Pacific Squadron based at Vladivostok. During the Russo-Japanese War of 1904–1905, he fought at the Battle of Tsushima. At the end of the battle, he refused to obey the order of Admiral Nikolai Nebogatov to surrender and broke through the Japanese blockade. The ship was however wrecked in the Gulf of Vladimir in the Russian Maritime Province. He received no punishment for his insubordination, and instead was promoted to captain 1st rank in 1905. In early 1906, Fersten was sent to suppress uprisings in Estonia against Russian rule in the unsettled times after the 1905 Russian Revolution. From 1906 to 1907, he returned to Vladivostok as commander of the Imperial Russian Navy base. From March 1908 to January 1909 he returned to Petrograd to command the cruiser. He was promoted to rear admiral in 1910 and commanded the 2nd destroyer division of the Baltic Fleet between 1909 and 1911 and the cruiser squadron of the Baltic Fleet from 1911 to 1913. On April 14, 1913, he was promoted to vice admiral and given command of the battleship squadron of the Baltic Fleet. He served on the General Staff of the Imperial Russian Navy during World War I and retired from service on April 13, 1917. After the Bolshevik Revolution, Fersen settled in his country house in Koze, Estonia, where he died in 1937. He had four children including Wladislaw Nikolai and Magnus Arvid von Fersen who also served as officers in the Imperial Russian Navy.
