George Lazenby was a model with no prior acting credits when he was cast as James Bond, having been noticed by producers via a Fry's Chocolate Cream advertisement.
Lazenby impressed Albert Broccoli by accidentally punching a professional wrestler acting as stunt coordinator in the face, which helped convince producers he could display the required aggression.
Lazenby dressed the part during his campaign for the role by wearing a Rolex Submariner watch and a Savile Row suit that had been ordered for, but never collected by, Sean Connery, and by going to Connery's own barber at the Dorchester Hotel.
Lazenby was offered a seven-film contract but was convinced by his agent Ronan O'Rahilly that the secret agent archetype would be outdated in the 1970s, so he left the role after this one film.
Over 400 actors were considered for Bond, including Terence Stamp, Oliver Reed, and Brigitte Bardot for the role of Tracy, though Bardot's deal fell through after she signed for Shalako opposite Sean Connery.
Richard Maibaum originally wrote the role of Blofeld with Max von Sydow in mind; von Sydow would later actually play Blofeld in the non-Eon film Never Say Never Again.
Gabriele Ferzetti, cast as Draco after producers saw him in We Still Kill the Old Way, had his voice redubbed for the final cut by English actor David de Keyser due to his heavy Italian accent.
George Baker, who played Sir Hilary Bray, also provided the dubbed voice for Bond whenever Lazenby's character impersonated Bray, since director Peter Hunt felt Lazenby's own impersonation was not convincing enough.
Filming took place at the Piz Gloria revolving restaurant atop the Schilthorn near Mürren, Switzerland, which was still under construction; producers agreed to finance its electricity and aerial lift to enable filming there.
A warm Swiss winter with inadequate snow cover previously forced Saltzman and Broccoli to postpone the film in favor of producing You Only Live Twice first.
Weak snowfall during production hampered the ski action scenes, and the Swiss shoot ran 56 days over schedule.
Cameraman Johnny Jordan developed a system where he was dangled by an 18-foot parachute harness rig below a helicopter, allowing dynamic aerial shots of the ski chase scenes.
Telly Savalas himself performed the stunt of Blofeld getting snared by a tree branch in the studio, after the stuntman's on-location attempt failed to look right.
For the stock-car chase scene, an ice rink was constructed over an unused airplane runway with water and snow constantly sprayed on it, and Lazenby and Rigg did most of the driving themselves due to the number of close-ups required.
The avalanche sequence was created by combining a man-made avalanche filmed by the second unit, stock footage, and special effects using salt, with stuntmen added afterward via optical effects.
Lazenby said director Peter Hunt never addressed him directly during filming, communicating only through an assistant, and reportedly asked the crew to keep their distance from him so Lazenby would feel more isolated in the role.
To get the desired emotional performance for Tracy's death scene, Hunt made Lazenby rehearse from 8 a.m. until he was completely exhausted before filming it at 5 p.m.
Two scenes were ultimately deleted from the final print: Irma Bunt spying on Bond buying a wedding ring, and a chase over London rooftops into the Royal Mail underground rail system.
John Barry composed the score without a title song containing lyrics, feeling the phrase 'On Her Majesty's Secret Service' would only work operatically; director Peter Hunt allowed an instrumental title theme instead, in the tradition of the first two Bond films.
Louis Armstrong recorded the love theme 'We Have All the Time in the World' in a single take despite being very ill at the time; the song was later reused as closing credits music for the 2021 film No Time to Die.
To reassure audiences it was still the same Bond despite the new actor, the filmmakers included in-jokes such as Bond breaking the fourth wall with 'This never happened to the other fellow,' a credits sequence with clips from earlier films, Bond finding gadgets from Dr. No, From Russia with Love, and Thunderball in his office, and a caretaker whistling the Goldfinger theme.
The original script included a subplot where Bond undergoes plastic surgery to explain his changed appearance, but this was dropped in favor of simply ignoring the change of actor.
On Her Majesty's Secret Service was the longest Bond film until Casino Royale was released in 2006.
Despite mixed contemporary reviews that often mocked Lazenby as 'The Big Fry' (referencing his chocolate advert past), the film's reputation has improved dramatically over time, with directors like Christopher Nolan and Steven Soderbergh citing it as their favorite Bond film.
In September 2012, the film topped a poll of Bond fans run by 007 Magazine to determine the greatest-ever Bond film, ahead of Goldfinger and From Russia with Love.
