In 1911, at the house of Mathilde Kschessinska, Prince Gabriel Konstantinovich met the young ballerina Antonina Rafaelovna Nesterovsky. There was an instant and strong attraction and soon the Prince was visiting Nina at her apartment in St Petersburg. They spent as much time as possible with each other, with Gabriel eventually renting a flat in the same building so as to minimize any scandal caused by prying eyes. He even timed his vacations abroad to match up with her professional travels, sometimes disappointing his parents by refusing family vacations to remain in Nina's company. A little over a year after meeting her, while in Monte Carlo in the spring of 1912, the pair decided to try and get engaged.
The Prince later wrote in his diary, "I wanted to marry [Nina] but I had no right to do this without the permission of the Emperor, not to mention the permission of my parents: I knew in advance that I would not get permission, but I decided anyway to get engaged." The couple found it difficult to locate a suitable member of the clergy to perform the ceremony of betrothal, but eventually settled on a monk from Athos who joined them on the afternoon of May 18th in the residence of Nina's uncle, Stepan Vassilievich Nesterovsky. To the relief of all, the ceremony went off without a hitch - though the prospective groom forgot his tie and had to borrow one.
So they were engaged. But the hurdle of how to get married was still a high one. Gabriel's parents seem to have been aware of his relationship with the ballerina, but apparently were not, prior to his father's death in 1915, aware that they were officially engaged. Gabriel's father, Grand Duke Konstantin Konstantinovich, wrote about "Gavrilusha's" relationship with a "concubine" who was his neighbor, but there is no evidence that he suspected Gabriel had stepped outside family boundaries and become betrothed.
Following Konstantin's death, Gabriel approached his mother on the question of his marriage to Nina, and received permission - which was given by the Grand Duchess when she was at an emotional low-point, and so Gabriel might not have been quite fair to her - but although regretting the permission she gave, she did not rescind it. From his mother, Gabriel took his campaign to his aunt, the Queen of the Hellenes, Grand Duchess Olga Konstantinovna. She, being a very direct personality, took the question straight to the Emperor. Nicholas was not angry at the request, but felt that he could not give his permission because it could then have opened the floodgates for other members of the family to want the same for their situations.
In late 1916, Gabriel received advice on how to proceed from a Dr Alexei Varavka who had treated one of the Empress's ladies-in-waiting; through this connection, rather than through his mother’s friendship with the Empress, the Prince approached Alexandra directly. Gabriel's diary for that time claims that she told him to get married and endure the consequences of exile, knowing that forgiveness would come in time, as it had for more senior members of the family. But within a few days, Prince Felix Yussupov and Grand Duke Dmitri Pavlovich, had murdered the monk Gregory Rasputin, and Gabriel, in supporting Felix and Dmitri in their actions, found himself on the opposite side of the issue from his widowed mother, and felt that he did not want to bring down more scandal and heartache on his family at that particular time.
But then came the February Revolution of 1917. And from Gabriel's point of view it brought one advantage: Romanovs were to be legally considered average citizens. And one of the perks of this status was the ability to enter into a marriage without obtaining the prior consent of the Emperor. His thought ran that if a Romanov were to take advantage of this new status - however short-lived before the expected restoration of the monarchy - then the new Emperor, whoever he may be, would be presented with a legal fait accompli and have no recourse other than to recognize the marriage as such - plus being as equal as it was on the day they married. And so, the wedding was planned for the first Sunday following Easter, 22 April 1917.
But Gabriel was not the only Romanov looking to get married on that day. His cousin, Prince Alexander Georgievich Romanovsky, wanted to marry the scandalously twice-divorced Nadezhda Nicholaievna Ignatieva. The decision was taken that they would marry on the same day in the same place, one right after the other, with Gabriel and Nina going first. The proposed Romanovsky marriage was already a topic of gossip, news of which the Empress wrote to the Emperor in 1916, " I heard that Sandro L. is going to marry a terrible woman - an Ignatieva, who was born Karalli - a 'cocotte' with a disgusting reputation. Her sister has been devastating old Pistolkors for three years now. I hope that this wedding can be stopped - it would be bad luck for that insane young man. "
The venue of the weddings was chosen: The Church of St Alexandra of Rome on Lermontov Avenue, which had been built in 1969 by the architect Karlamov. The Church was directly connected to the neighboring orphanage founded by Nicholas I in memory of his daughter Alexandra, who had died in childbirth at the age of nineteen. Both the grooms were relatives of this unfortunate Grand Duchess, though whether this family connection drew them to this venue is unknown.
Shortly before the wedding, Gabriel invited his older brother Ioann, with whom he had always been very close, to attend as his supporter, and Ioann agreed - but he evidently changed his mind and did not appear at the appointed time. At 3pm, Gabriel made his way to the Church in the company of his soon-to-be sister-in-law and a friend, Prince Barclay de Tolly-Weymarn. Nina drove to the Church in the car of their friend A.I. Putilov, accompanied by her aunt and her sister's husband. Gabriel gave this driver a letter to be delivered to his mother immediately, informing her of the marriage. Somewhere in the to-ings and fro-ins of the afternoon, Gabriel's brothers Prince Konstantin and Prince George realized that the wedding was happening, and hurried home to change and then dash to the Church to attend. They remained after Gabriel's wedding to support Alexander Romanovsky, and Gabriel went on to the Marble Palace, where he received his mother's blessing, though she did not agree to see Nina at that time.
With an eye to the future, and what he expected would be a quick restoration of Romanov rule, Gabriel and Nina sent a telegram to Grand Duke Michael Alexandrovich, the former Emperor's younger brother whom many people expected would be offered the throne in due course. Michael Alexandrovich, himself involved in an unequal marriage, sent a congratulatory message in return.
Neither couple who married that day had children. Both couples eventually fled Russia through Finland and made their way eventually to France. The church where they married was razed in 1938 and replaced with nothing.