The series was remarkable for pairing an American, Napoleon Solo, and the Russian Kuryakin as two spies who work together for an international espionage organisation at the height of the Cold War. Kuryakin was played by Scottish actor David McCallum.
Although originally conceived as a minor character, Kuryakin became an indispensable part of the show, achieving co-star status with the show's lead, Napoleon Solo. McCallum's blond good looks and the enigmatic persona he created for the character garnered him a huge following of female fans. Such was the popular hysteria surrounding him that he was referred to in newspaper reports at the time as "the blond Beatle" or "the fifth Beatle". While playing Kuryakin, McCallum received more fan mail than any other actor in the history of MGM.
Much of the character's appeal was based on what was ambiguous and enigmatic about him. When an acute reaction to penicillin hospitalized him in the early days of filming the series, McCallum took the opportunity to give serious thought to how he might flesh out what was, at that stage, a sketchy peripheral character. The approach he hit upon was to build a persona based on ambiguity and enigma, hiding, rather than revealing, aspects of the character's background and personality. McCallum summed up the character in commenting "No one knows what Illya Kuryakin does when he goes home at night."
Kuryakin is consistently referred to as a "Russian"; however, he appears to have spent at least some of his childhood in Kiev, Ukraine ("The Foxes and Hounds Affair"). He is Number Two in Section Two (Operations and Enforcement) at U.N.C.L.E. headquarters in New York City. He seems to be a Soviet citizen of good standing rather than a defector. In "The Neptune Affair" he appears in the uniform of the Soviet Navy and is recalled to the USSR to help deal with a crisis. Despite the series being aired at the height of the Cold War, no great issue is made of Kuryakin's nationality and politics.
In the film The Spy with My Face, he claims to have been "the first lieutenant in the Russian navy to set fire to an igloo," although it is possible this story was invented to entertain his companion.
He identifies his father as being "the eleventh son of Kuric," a Gypsy leader ("The Terbuf Affair"), but later admits he fabricated the story to gain the trust of the local Gypsies (who are not fooled). Nonetheless, some fans theorize some of the story may be true as there is a name link (Kuric / Kuryakin), Kuryakin is an expert on the Gypsy culture and traditions, and Solo makes a reference in one of the spin-off novels to his partner's "Gypsy heritage." His attitude to women contrasts with that of his partner; they chase him, but he rarely pursues them.
He holds a Master's degree from the Sorbonne and a PhD in Quantum Mechanics from the University of Cambridge ("The Her Master's Voice Affair"). He appears to have been an undergraduate at the University of Georgia in Tbilisi (though he states Georgia itself is in "the Ukraine"), where he practiced gymnastics ("The Hot Number Affair"). Kuryakin is a polymath. He is well-read in English literature, he has an in-depth knowledge of music and plays the bass viol, the English horn and guitar. He also sings, and he speaks many languages, including French, German, Italian and Japanese.[episode needed]