Eugenia Maximilianovna of Oldenburg, born Romanovskaya, was born on March 20 (April 1) 1845. She was the fourth child and third daughter of Grand Duchess Maria Nikolaevna and Duke Maximilian of Leuchtenberg from Bavaria. Her paternal great-grandmother, Maria Françoise-Joséphine, was the French Empress and the first wife of Napoleon I.

After her father's death in 1852, Nicholas I granted her family the title of Imperial Highnesses of the Romanov princes. Eugenia spent her childhood and youth in St. Petersburg. Her upbringing, along with that of her elder sister Maria, was overseen by Elizaveta Andreyevna Tolstaya, a cousin of Leo Tolstoy. In 1857, Tolstoy met the 12-year-old Eugenia in Geneva and later wrote about her as a charming and simple girl.

Eugenia stood out at court for her extravagance, preferring a semi-masculine style of clothing. In 1868, she married Prince Alexander Petrovich of Oldenburg, and that same year they had a son, Peter. In 1878, she acquired the estate of Ramony near Voronezh, which included a beet sugar factory.

Eugenia was actively involved in social and cultural life. She was the president of the Mineralogical Society and an honorary member of several charitable organizations. For some time, she headed the Imperial Society for the Encouragement of the Arts and established an art prize. She also contributed to the creation of art schools and the publication of a collection of artistic-industrial drawings.

Eugenia was a patron of the Red Cross Sisters' community, which later became the St. Eugenia Community. The community published artistic postcards that became popular. In 1898, the postcards went on sale, and over 20 years, more than 30 million copies were produced.

Since 1868, Eugenia was the patron of the Christmas Women's Gymnasium, later renamed in her honor. She also supported the House of Mercy and the Maximilian Hospital. During the Russo-Japanese War, she headed the committee to assist wounded soldiers.

From the 1880s, Eugenia lived at the Ramony estate, where she was actively engaged in economic activities. She restructured the estate along capitalist lines, reconstructed factories, and opened new productions. She also cared for schools and hospitals in Ramony.

Eugenia and her husband Alexander took an oath to the Provisional Government after the 1917 revolution. After the revolution, she lived for some time in Petrograd, then moved to Finland and France, where she lived until the end of her life. Eugenia Maximilianovna passed away on May 4, 1925, at the age of 80.