In the weeks which preceded his breakthrough time of 3 minutes, 59.4 seconds on that damp and windy day at Oxford's Iffley Road track, his great Australian rival John Landy, who had already run 4:03 on five occasions, declared that the four-minute mark for the mile was "like a wall".
Even so, the Australian was reported to be running miles of 4:02 solo while training on rough tracks, and in the meantime United States runner Wes Santee was declaring his own intention of breaking the record in the spring. So Bannister, and his coach Franz Stampfl, knew there was an urgent need to attack the mark.
On June 21, 1954, in Turku, Landy set a world mile record of 3:58.0 (rounded up, through the International Association of Athletics Federations (IAAF) system of the time, from 3:57.9). So much for the wall. But would the Australian have managed such a performance had his English rival not produced that historic effort 46 days earlier?
Bannister's take on "the wall" was that it simply didn't exist. As a medical student, he felt sure that if the distance had already been run in 4:01.4, the world record set in 1945 by Sweden's Gunder Hägg, it could come down further with a combination of better conditions, training and pace judgement.
The nearest equivalent to the four-minute mile in today's athletics is probably the two-hour marathon. The current world record, held by Kenya's Wilson Kipsang, stands at 2hr 03min 23sec, and Bannister believes the two-hour mark will be broken in the next few years.
"It involves a two per cent improvement," he told Associated Press last week. "It will be done."
But what of the world mile record?
In the wake of his epochal effort, Bannister borrowed the words attributed to Louis XV of France: "Après moi, le déluge" - "After me, the flood". He was not wrong.
Starting with Landy's, there have been another 18 world mile records set, and the current mark stands at 3:43.13, set at Rome's Olympic Stadium in 1999 by Morocco's Hicham El Guerrouj.
On the eve of the 40th anniversary of the four-minute mile, Bannister and the two runners who had paced him on that occasion, Chris Brasher and Christopher Chataway, attended a celebration dinner at Grosvenor House in London, to which 14 other holders of the world mile record - before and after the Oxford landmark - were invited.
Inevitably, the question of how much faster the mile could be run in future was put to numerous attendees, including, naturally, Bannister himself.
Eight months earlier, Noureddine Morceli of Algeria, one of those present at the gathering, had lowered the record to 3:44.39 in Rieti, eclipsing the mark of 3:46.32 set by Britain's Steve Cram in the 1985 Oslo Dream Mile.
Morceli, of course, inhabited a different athletics world to Bannister: shale or cinder tracks had been replaced with artificial composite surfaces, shoe technology and training methods were massively advanced.
Despite all that, US runner Jim Ryun - who had twice broken the world mile record, running 3:51.3 in 1966 and lowering his own mark to 3:51.1 the following year - opined: "I don't think we will see a 3.30mile in my lifetime."
For his part, New Zealand's triple Olympic champion Peter Snell, who had also lowered the mile record to successive levels with 3:54.4 in 1962 followed by 3:54.04 - rounded up officially at the time to 3:54.1 - in 1964, felt that times could not fall any further.
"This is the guy," he said, gesturing across at Morceli. "I think he's had the last shot at the record." The Algerian responded with raised eyebrows - at the time, he was still planning to trim another couple of seconds off his mark.
However, the man whose world record of 3:45.5 Snell beat, Australia's Olympic champion Herb Elliott, viewed the future very differently.
"I believe there will be a quantum leap somewhere in the equation," he said. "I don't think we yet understand fully about the interface between the mind and the body."
And Bannister? Well, he was more closely aligned with his US successor Ryun, stating that 3.30 looked like the ultimate mark possible with significant genetic experimentation.
"For it to happen," he said, "perhaps in the early part of the next century, we would have to have a period of peace in the world and for populations such as the Indian and Chinese to produce the genetic variety of mind and body to reach towards that time.
"A strong heart and lungs to breathe in the air, the ability to tolerate the pain through the build-up of lactic acid and avoiding over-training, which can break down the immune system - these are three factors which will help get down to 3.30."
In response to the report of these predictions, The Independent's letters page received an intriguing item from The Reverend Dr W M Rumball, of Derbyshire, who cited a research paper he had written with colleague Dr Kit Coleman which had been published in a 1970 issue of the science journal Nature.
Rumball, a keen club runner, said he had been working on the "bonding orbitals of transition metals" at a laboratory in Ontario, Canada when, in what he described as "a bizarre bit of lateral thinking" led him to the following discovery:
"For any one individual, the rate of anaerobic running (the inverse of speed) declines linearly with the logarithm of the total distance run, and that the coefficient of that decline (I call it the 'fatigue coefficient') could be used to predict the optimum distance to be run by any athlete."
The published research, Rumball added, concluded with the prediction that "the ultimate mile record would be three minutes exactly (and the ultimate marathon would be run in one hour, 37 minutes, 30 secs!). We further speculated that the ultimate mile would be run by 2070."
Time will tell...
Bannister's effort in that Thursday afternoon match between the Amateur Athletic Association and Oxford University was opportunistic in terms of what his rivals were doing - and also, as he has made clear in his autobiographical works The First Four Minutes (1980, Sutton Publishing) and the recently published Twin Tracks, in terms of the weather on the day.
Having taken the train up to Oxford on the morning of the race from London, where he was a medical student at St Mary's Hospital, Bannister was met at the station by an old friend, Charles Wenden, and walked around the track with him, noting that "the wind was almost gale force", before driving to Wenden's house for lunch with his young family. The domestic routine calmed and distracted him.
Later he called in on Chataway, who stretched out on a window-seat as the sun began to shine: "Chris smiled and said, just as I knew he would, 'The day could be a lot worse, couldn't it?'"
As a small crowd which included a tipped-off BBC cameraman waited to see whether the attempt was on or not, Bannister stood inside the changing room trying to judge if the weather was getting worse and - by his own admission - annoying his two friends. "I was watching the flag of St George on the Iffley Road church and I saw that it was not standing out," he recalled. Attempt on.
But if some elements of that day had to be left to chance, others were meticulously planned.
In mid-morning, Bannister had sharpened his spikes on a grindstone in the laboratory at St Mary's Hospital, and recalled that a passer-by had said to him: "You don't think that's going to make any difference, do you?"
Bannister did. The spikes, made specially for him with the guidance of a climber and fell-walker, Eustace Thomas of Manchester, needed to be sharp. "If they had collected a lot of sticky ash it might have made a difference of two or three yards," Bannister wrote.
A false start to the mile aroused some anxiety in him that the precious lull in the weather was being wasted. Photographs taken at the quarter-mile mark show the St George flag standing out once again in front of a dark sky - but by then Bannister was running effortlessly. "My legs seemed to meet no resistance at all," he wrote.
He shouted to Brasher, who led through the first lap in a sensible 57.5sec, to go faster. "At one and a half laps I was still worrying about the pace," he wrote. "A voice shouting 'relax' penetrated to me above the noise of the crowd. I learned afterwards it was Stampfl's."
The half-mile passed in 1.58, and round the next bend Chataway took over from Brasher. Three-quarters of a mile was reached in 3:00.7. A 59-second last lap was required.
After moving past Chataway with three-quarters of the last lap remaining, Bannister recalled: "I felt that the moment of a lifetime had come. The world seemed to stand still, or did not exist. The only reality was the next 200 yards of track under my feet. The tape meant finality - extinction perhaps. I felt at that moment it was my chance to do one thing supremely well...
"I leapt at the tape like a man taking his last spring to save himself from the chasm that threatens to engulf him."
In the ferment which followed, timekeeper Norris McWhirter began upon a long and tantalising announcement which he was prevented from finishing by a general roar of excitement:
"As a result of Event Four, the one mile, the winner was R G Bannister of Exeter and Merton colleges, in a time which, subject to ratification, is a track record, an English native record, a United Kingdom record, a European record, in a time of three minutes..."
Forty years on, Bannister and Brasher stood on the same track at the conclusion of a Handicap Mile, involving some of the world's most celebrated past performers (although not Bannister himself, who has been unable to run since shattering his ankle in a road accident in 1975).
On this occasion, Bannister was half-jokingly, half-solicitously taking his fellow 65-year-old's pulse. "It's under 100," he said with a twinkle.
Ten years later, Bannister was back for another media occasion at Iffley Road to tie in with the 50th anniversary of his run. After being pressed, as it were, to recount his former glories in great detail, he turned to the man sitting alongside him, UK Athletics President Lynn Davies, and made a point of saying that the Welshman had earned something which he had never managed - an Olympic gold medal.
It was a gesture of respect to the long jump victor of the Tokyo 1964 Olympic Games - and another badge of honour for this immensely gifted, immensely modest man.
In previous years, Bannister has met up on the anniversary of that momentous race with the two men who helped him. Now, alas, that reunion is no longer possible.
To mark the latest anniversary, the 85-year-old Bannister, who is suffering from Parkinson's Disease - a neurological condition with which, as a former neurological surgeon, he is uncomfortably familiar - will celebrate with his wife of 58 years, Moyra, and family and friends as they gather for lunch at Exeter College, Oxford before taking part in a ceremony at the university city's Vincent's Club, the 150-year-old sporting establishment.
As he reflected once again last week on the moments of high endeavour by his 25-year-old self which indelibly re-wrote the history of track athletics, he commented with characteristic restraint: "It was just something which caught the public's imagination. I think it still remains something that is of interest and intrigue."
You think correctly, Sir Roger...
Mike Rowbottom, one of Britain's most talented sportswriters, covered the London 2012 Olympics and Paralympics as chief feature writer for insidethegames, having covered the previous five summer Games, and four winter Games, for The Independent. He has worked for the Daily Mail, The Times, The Observer, The Sunday Correspondent and The Guardian. His latest book Foul Play – the Dark Arts of Cheating in Sport (Bloomsbury £12.99) is available at the insidethegames.biz shop. To follow him on Twitter click here.