Prince Esper Beloselsky was born on the estate of his parents, General Konstantin Esperovich and Nadezhda Dmitrievna, the sister of a general. He served in the Russian Imperial Navy as an officer in the rank of a captain. As an officer in an elite corps, he was a crew member on the imperial yachts Alexandria and Polar Star. With the beginning of the revolution on the Kronstadt island naval base, he barely avoided capture. He first fled to Finland and in 1919 left for France, where he died a few years later from stomach cancer. With his first wife, Olga Alexandrovna, he had one son, who was murdered during the revolution, and one daughter. Beloselsky probably married his second wife, Madeleine Julie Moulin (later de Tselebrovsky) from France, without being properly divorced. Their two sons used her mother’s surname. They were later officially recognized by their father.
Since childhood, he was connected to sports through his older brother Sergey, Prince Beloselsky-Belozersky, who was a member in the IOC and also headed various sports federations. His father was already an honorary member of the Imperial Yacht Club, when Esper Beloselsky joined the club in 1909. He was a member of the crew of the “Gallia II” in the 10-metre class at the 1912 Olympic Games. In the match race for the second place they lost to the Finnish yacht “Nina” to win bronze.