Immediately after her father's tenure (1883–1887) as a police commissioner of the New York Police Department, Julia Dent Grant traveled to Europe in the company of her maternal aunt, Bertha Palmer (née Honoré) who was representing the Board of Lady Managers of the World's Columbian Exposition (Chicago World's Fair.)
 From 1891 to 1893, aunt and niece travelled throughout Europe to promote interest in the Exposition as well as to collect art.
 Julia met Prince Mikhail Cantacuzène, who was attached to the Russian embassy in Rome.
Prince Michael (or Mikhail) was Prince Mikhail Cantacuzène, son of Prince Mikhail Rodionovich Cantacuzène and Elizabeth Siscard, was born on 29 April 1875 in Odessa, Russia.
 He was a distant relative of Grigorii L'vovich Kantakuzen, who was the Russian representative to the U.S. from 1892 to 1895.
 Two weeks after their first meeting in Rome, Prince Cantacuzène followed Julia to Cannes, ostensibly to serve under Grand Duke Kyrill.
 After a courtship of two days, the couple became engaged in Cannes, then embarked upon four months of wedding preparation, during which time they were separated.
 The couple married at Beaulieu, an Astor home which her aunt Bertha Palmer had leased for the summer season, in Newport, Rhode Island, in a small, private Russian Orthodox ceremony the evening of  24 September 1899.
 The following day at noon there was an Episcopal Church wedding service in All Saints' Memorial Chapel, Newport.
After her marriage, she combined her names, titles, and styles in a Russian manner as Julia Dent Cantacuzène Spiransky-Grant; however, she was commonly referred to as Princess Julia Cantacuzène or Princess Cantacuzene.

Prince and Princess Cantacuzène resided in St. Petersburg (later Petrograd) or at their estate in Ukraine during their early married years, with the Princess giving birth to their three children, Mikhail Mikhailovich, Barbara or "Bertha" Mikhailovna, and Zinaida Mikhailovna.
 Princess Cantacuzène remained in St. Petersburg during World War I in which Prince Cantacuzène served as aide-de-camp and later Major-General, and finally General, in the service of Tsar Nicholas II.
 He served with distinction and was wounded in battle in 1914; as commander of the South Russia Cossacks, in 1915 he led 15,000 men in what has been called the last great cavalry charge against a fortified position in military history.
 The family left Russia in the aftermath of the Russian Revolution; in 1917, they escaped from Petrograd with her jewels sewn into her clothing, and escaped via Finland to the United States.
The couple moved to Washington, D.C. and attempted to attract support for a counter-revolution in Russia, but after news of the assassination of the Tsar and of his brother, Grand Duke Michael Alexandrovich of Russia, ended their activism.
 The couple relocated to Sarasota, Florida, joining the firm founded by her aunt Bertha Palmer.

Prince and Princess Cantacuzène divorced on 27 October 1934, after which Mrs. Julia Grant Cantacuzène, having re-established her U.S. citizenship and reverted to non-aristocratic title and style, moved back to her native Washington, D.C.
Immediately after her father's tenure (1883–1887) as a police commissioner of the New York Police Department, Julia Dent Grant traveled to Europe in the company of her maternal aunt, Bertha Palmer (née Honoré) who was representing the Board of Lady Managers of the World's Columbian Exposition (Chicago World's Fair.)  From 1891 to 1893, aunt and niece travelled throughout Europe to promote interest in the Exposition as well as to collect art.  Julia met Prince Mikhail Cantacuzène, who was attached to the Russian embassy in Rome. Prince Michael (or Mikhail) was Prince Mikhail Cantacuzène, son of Prince Mikhail Rodionovich Cantacuzène and Elizabeth Siscard, was born on 29 April 1875 in Odessa, Russia.  He was a distant relative of Grigorii L'vovich Kantakuzen, who was the Russian representative to the U.S. from 1892 to 1895.  Two weeks after their first meeting in Rome, Prince Cantacuzène followed Julia to Cannes, ostensibly to serve under Grand Duke Kyrill.  After a courtship of two days, the couple became engaged in Cannes, then embarked upon four months of wedding preparation, during which time they were separated.  The couple married at Beaulieu, an Astor home which her aunt Bertha Palmer had leased for the summer season, in Newport, Rhode Island, in a small, private Russian Orthodox ceremony the evening of  24 September 1899.  The following day at noon there was an Episcopal Church wedding service in All Saints' Memorial Chapel, Newport. After her marriage, she combined her names, titles, and styles in a Russian manner as Julia Dent Cantacuzène Spiransky-Grant; however, she was commonly referred to as Princess Julia Cantacuzène or Princess Cantacuzene.
Prince and Princess Cantacuzène resided in St. Petersburg (later Petrograd) or at their estate in Ukraine during their early married years, with the Princess giving birth to their three children, Mikhail Mikhailovich, Barbara or "Bertha" Mikhailovna, and Zinaida Mikhailovna.  Princess Cantacuzène remained in St. Petersburg during World War I in which Prince Cantacuzène served as aide-de-camp and later Major-General, and finally General, in the service of Tsar Nicholas II.  He served with distinction and was wounded in battle in 1914; as commander of the South Russia Cossacks, in 1915 he led 15,000 men in what has been called the last great cavalry charge against a fortified position in military history.  The family left Russia in the aftermath of the Russian Revolution; in 1917, they escaped from Petrograd with her jewels sewn into her clothing, and escaped via Finland to the United States. The couple moved to Washington, D.C. and attempted to attract support for a counter-revolution in Russia, but after news of the assassination of the Tsar and of his brother, Grand Duke Michael Alexandrovich of Russia, ended their activism.  The couple relocated to Sarasota, Florida, joining the firm founded by her aunt Bertha Palmer.
Prince and Princess Cantacuzène divorced on 27 October 1934, after which Mrs. Julia Grant Cantacuzène, having re-established her U.S. citizenship and reverted to non-aristocratic title and style, moved back to her native Washington, D.C.
Julia Dent Cantacuzène Spiransky-Grant