Grand Duke Konstantin Nikolayevich of Russia [SEP] father
Grand Duke Konstantin Nikolayevich of Russia
Grand Duke Konstantin Nikolayevich of Russia (; 21 September 1827 – 25 January 1892) was the second son of Tsar Nicholas I of Russia and younger brother of Tsar Alexander II. 
During the reign of Alexander II, Konstantin was an admiral of the Russian fleet and reformed the Russian Navy. He was also an instrumental figure in the emancipation of the serfs. He was less fortunate as viceroy of Poland (1862–1863) and had to be recalled to Russia where he was attacked for his liberalism
of the famous philosopher Friedrich Nietzsche. Her sisters included Queen Marie of Hanover (wife of George V of Hanover) and Grand Duchess Alexandra Iosifovna of Russia (wife of Grand Duke Konstantin Nikolayevich of Russia). Through Alexandra, Elisabeth was an aunt of Queen Olga of Greece.
Marriage.
On 10 February 1852, Elisabeth married her second cousin Peter, Hereditary Grand Duke of Oldenburg. He would succeed his father the following year as Grand Duke, making Elisabeth Grand Duchess of Oldenburg. She used funds given to her