[4] Esterhase is known for multiple eccentricities, including "dressing like a male model," washing his own clothes rather than having them laundered,[5] never smiling,[6] and sending all of his colleagues bottles of alcohol for Christmas.
[7] Guillam further recounts that Esterhase appears impervious to fear, recalling an incident in which he stopped to tip several Swiss hotel employees while fleeing would-be captors.
Despite his odd behaviour, Esterhase proves himself to be a valuable spy and extremely competent at his job; characters often find themselves conflicted between being put off by his eccentricity and being glad to have him on their side.
Esterhase personally assembled the Lamplighters by recruiting housewives, vagabonds, and other individuals whom no one would suspect of espionage work, and honing them into an efficient, tightly-knit unit that becomes something of a surrogate family for them.
Esterhase is motivated by a desire to be accepted by his peers as a true English gentleman, a weakness exploited by Percy Alleline to coax Toby into supporting him in a coup against Control, the head of the Circus.
Smiley later uses the same desire for acceptance to convince Esterhase to switch alliances and support him in exposing Alleline as a fraud whose arrogance has blinded him to the presence of a mole in his inner circle.
A Hungarian national, Smiley found Esterhase in Vienna as a starving student living in the ruins of a museum of which his late uncle had been curator.
During a posting to Bern, Switzerland, for example, the pair came under suspicion for organising acts liable to be considered a seditious conspiracy by the local police and were forced to flee the country.
Following the failure of Operation Testify and the presumed death of Jim Prideaux in 1973, Esterhase supported Sir Percy Alleline's successful attempt to oust Control as Chief of the Circus.
In the aftermath, Esterhase, Bill Haydon and Roy Bland form the "magic circle" alongside Alleline, using their exclusive access to "Merlin", a Soviet intelligence source handled by Operation "Witchcraft", to assume leadership of the Circus.
[17] By 1977, the year of Smiley's People, Esterhase is retired from British Intelligence and operates a second-rate art gallery in London selling forgeries of Edgar Degas and other artists.
Esterhase is one of the central characters in a farcical vignette in which he gets rid of a charlatan—an exiled Hungarian professor based in Munich,[22] who provides the British with virtually worthless information—by successfully convincing the CIA that he is a dauntless anti-Communist hero.
[23] Esterhase is briefly mentioned in a cameo role in A Legacy of Spies where he, together with Percy Alleline and Roy Bland, meet Peter Guillam at the field dispatch office at Heathrow Airport during a flashback; whether Toby is still alive in the present day is not revealed.
Le Carre] came to write his novel Tinker, Tailor, Soldier, Spy, he would draw on Deutsch for his character Toby Esterhase, who like his original would speak his own form of English.Le Carre himself described double agent George Blake as another part-inspiration, feeling some—perhaps misplaced—sympathy for "the wretched man" on account of his status as a foreigner ("half a Dutchman and half a Jew") in the British intelligence establishment.