Hugo William Koehler (July 19, 1886 – June 17, 1941) () was a United States Navy commander, secret agent and socialite. Following the First World War, he served as an Office of Naval Intelligence and State Department operative in Russia during its civil war, and later as naval attaché to Poland. He was rumored to be the illegitimate son of the Crown Prince of Austria and to have assisted the Romanovs in fleeing Russia following the revolution of 1917. He was awarded the Navy Cross for his service during World War I and was the step-father of United States Senator Claiborne Pell (1918–2009). Early life and family history Hugo W. Koehler was born on July 19, 1886, in St. Louis, Missouri, and named after a paternal uncle. His father, Oscar C. Koehler (1857–1902), was a first-generation German-American and second-generation St. Louis and Davenport, Iowa brewer and entrepreneur. Although it was privately rumored for much of his life that Hugo was the illegitimate son of Rudolf, Crown Prince of Austria, who is generally believed to have died with his teenage mistress, Baroness Mary Vetsera, in a murder-suicide pact in January 1889 (the "Mayerling incident"), no corroborating evidence of this ancestry has been established. The speculation was fueled by a few factors: 1) Koehler, who was reputed to be the "wealthiest officer" in the American navy in the 1920s, was apparently the beneficiary of a substantial trust fund. It was further speculated that this trust had been established by the Habsburgs with approval of the Holy See when Hugo Koehler was a child, to provide for his support and maintenance; 2) As a child, Hugo made several European visits with his paternal grandfather, Heinrich (Henry) Koehler, Sr. (1828-1909), where he was introduced to aristocracy and elites; and 3) Koehler had the distinctive Habsburg chin. Ironically, in 1945, The New York Times published a story that a German lithographer by the name of "Hugo Koehler", following his death at the age of 93, was revealed to be Archduke Johann Salvator of Austria, son of Leopold II, Grand Duke of Tuscany and a member of the Imperial Austrian Habsburg family. Johann had been a witness to the tragic events at Mayerling in 1889. Rudolf, unsatisfied in his marriage to Stephanie, daughter of Leopold II of Belgium had found romance with Mary, the younger daughter of a Hungarian earl. Taking her along on a party