Here is a sampling of the many names and identities associated with Reilly:Son of Irish seaman
Since it really doesn't matter what his original name was, we will call him "Sidney Reilly," which was the name he later adopted after he began working for British intelligence.
Not surprising to anyone who has researched Reilly, there are also competing narratives as to what Reilly was doing as a young man. A master of deception from his earliest days, it's a very good chance the "Ace of Spies" made up the majority of these stories.
One legend is that as a young man of 19, Reilly stowed away on a British ship from Russia bound for Brazil where he took the name "Pedro" and worked as a dishwasher, cook and a bouncer. He would then serve on an expedition into the Amazon where he befriended British explorers. On this expedition Reilly is said to have saved the life of the explorers, among them Major Charles Fothergill, when the group was attacked by cannibals. Reilly grabbed a British pistol and shot several of them dead. Fothergil recognizing his bravery gave Reilly 1,500 pounds, a British passport and sent him to England where he recommended Reilly for the British intelligence service. Once in England "Pedro" became "Sidney Rosenblum."
Other stories (perpetuated by Reilly himself) include tales of being a brothel doorman, a railway worker in India and a spy for the Japanese government. Another backstory was that at some point he had been an Irish pastor.
Some historians believe Reilly never actually went to Brazil and in fact came to London from France where he was on the run from the December 1895 murder and theft of two Italian anarchists in Paris. Reilly and his accomplice Yan Voitek had supposedly robbed the anarchists of their "revolutionary funds" and killed the men in the commission of the theft.
In 1896 the facts of his life become less opaque when Reilly now in London became a paid informant for Scotland Yard. While many thought of him as a "scoundrel" and a "criminal," Reilly spoke 7 languages and was extremely cunning and as such was a perfect recruit for British intelligence.
In 1897 he began an affair with Margaret Thomas, the wife of Reverend Hugh Thomas, who soon after died of mysterious circumstances leaving her with a fortune of Â£800,000. Four months after the death of Rev. Thomas the lovers married and the now wealthy Reilly took on the official identity "Sidney George Reilly."
What followed were several years of intrigue and spycraft including working as a double agent for the British, Japanese, Tsarists and other highest bidders for Reilly's services.
Reilly was said to have a natural flair for his work, a master of disguise who was cool-headed and brave. He took on the most dangerous assignments and was always willing to risk his life for his work. He also lived a life of luxury. Along with the cash he was given to bribe various officials on his assignments he was also provided with a hefty salary. Since he was primarily loyal to his bank account it made him an easy recruit for multiple intelligence agencies.
Reilly was married several times during his short life (people who knew him joked that he had more wives than fake passports, of which had many), and was known to have a reputation for womanizing. He was "popular with the ladies" with a "seductive charm" but "never forgot to keep his bank account topped up as he adored his affluent lifestyle, womanizing, and gambling."
In 1906 he moved to St Petersburg where posing as a wealthy businessman with a "lavish apartment" and money to spare he spied for both the British and Tsarist government and became acquaintances with members of the revolutionary underground.
One exploit in France known as the "D'arcy Affair" had Reilly disguised as a Catholic priest to sneak on to a yacht purportedly seeking charity. He was then able to pull aside engineer William Knox D'Arcy, the holder of huge Persian oil concessions, and convince him to sell the oil to the British rather than the French, which became a huge benefit to the British economy.
Another escapade involved Reilly and another British agent stealing technology called a "magneto" from a German airplane that had just crashed (killing the pilot) at the Frankfurt International Air show in 1909.
Also in 1909 Reilly went undercover as a shipbuilder named Karl Hahn working in a German gun works plant. He was sent on the mission because the British knew very little about what the German Kaiser was doing in terms of building up armaments and needed intelligence. Once there Reilly picked the lock of an office and reportedly killed a foreman who had discovered the theft.
Leading up to World War I, Reilly working for Germany ship builders and was able to provide the British with blueprints of Germany's naval development plans. In subsequent years he worked in NYC as both a Russian and German arms dealer. He was also believed to have helped prevent German sabotage of American factories.
During World War I he made many missions across enemy lines into Germany once even attending a meeting in the presence of Kaiser William II.
In 1918 Reilly and several others were sent to Russia in an effort to defeat the nascent Bolshevik government. After the plot to lead a coup against Lenin failed Reilly barely barely escaped capture by the Cheka (Soviet secret police), fleeing his apartment 30 minutes before their arrival to arrest him. Reilly was condemned to death by the Soviets in a trial by absentia. In December 1919, he was awarded a Military Cross for this dangerous mission.
What followed were several years of plots to topple the Soviet regime working with various factions including former Okhrana agents, "Whites" and other opponents of the Bolsheviks.
In 1925 Reilly was captured in Moscow after being told by London authorities that it would be unsafe to return. He had been lured back to Russia via Finland by a fake resistance group manufactured by the OGPU (formerly called the Cheka). Tried for crimes against the Soviet government he was executed by gunshot in a forest near Moscow on November 5, 1925.