Speaking to the organising team's magazine before this year's race Kipchoge - who won the Rio 2016 and Tokyo 2020 titles - commented:

"Berlin is like home for me.

"In view of the Olympic Games next year in Paris, I thought about which race could be the best preparation for the Games for me and Berlin is the best option."

Kipchoge’s memories of the German capital could hardly be warmer. Running there last year, he took a full 30 seconds off his own world record, set on the same course four years earlier, reducing it to 2hour 01min 09sec.

It was his fourth victory in Berlin following earlier triumphs in 2015, 2017 and 2018, bringing him level with that other fabled runner Haile Gebrselassie, who had four consecutive wins there from 2006 to 2009. Another record to go for today.

Are you sitting down? There was one occasion when Kipchoge ran the Berlin Marathon and didn’t win. I know. It was in 2013, and he finished second, in 2:04:05, behind the world record of 2:03:23 set by compatriot Wilson Kipsang.

Kipchoge didn’t lose in the marathon again until the London 2020 race…

As things stand, in Olympic terms, he shares a podium with two other figures.

Ethiopia’s Abebe Bikila, then 28, carried high hopes into the Rome 1960 Olympics. Having won his first marathon earlier in that year, in Addis Ababa, he ran a second race in the home capital and recorded a time of 2:21:23, which was faster than the existing Olympic record set in Helsinki by the Czech runner Emil Zatopek in 1952.

In Rome, ahead of the race on September 10, Bikila bought some new running shoes. But they did not fit well and gave him blisters. So he decided to run barefoot.

To avoid the worst of the oppressive midday heat, the race began late afternoon at the foot of the Capitoline Hill and finished at night at the Arch of Constantine, just outside the Colosseum.

Around the 25 kilometres mark (16 miles) Bikila and Morocco’s Rhadi Ben Abdesselam moved clear of the rest of the field and remained together until the final 500 metres, when the Ethiopian sprinted away down the Appian Way, which was lined with soldiers holding torches on long poles, before finishing in a world record of 2:15:16.2.

At the Tokyo 1964 Olympics, Bikila toed the line in defence of his title, wearing Puma shoes, just 35 days after being rushed into hospital for an appendectomy.

Shortly before the 20km (12mile) mark, with Australia’s Ron Clarke flagging, Bikila took a lead he never lost. 

He finished more than four minutes clear of his nearest rival, Britain’s Basil Heatley, who had started the race as world record holder with a time of 2:13:55, set earlier in the year, and who finished it as ex-world record holder. Bikila’s winning time was 2:12:11.2.

Having been roared round his final, solitary tour of the track by the 75,000 crowd, this member of the Ethiopian Imperial Guard put on a carefree show for them as he performed a routine of calisthenics which included touching his toes and then lying down and cycling his legs in the air.

On March 22, 1969, Bikila overturned his VW Beetle trying to evade on oncoming car and was left paralysed from the neck down. He regained the use of his arms, and competed in the 1970 Stoke Mandeville Games in archery and table tennis.

Bikila died on October 25, 1973, aged 41, of a cerebral haemorrhage related to his accident.

East Germany’s Waldemar Cierpinski was virtually unknown when he entered the Montreal 1976 Olympics marathon. He ran with the lead pack until defending champion Frank Shorter of the United States moved clear after 25km. Cierpinski chased Shorter down and then took the lead, winning the race by 51 seconds in an Olympic record of 2:09:55.

Four years later in Moscow, Cierpinski retained his title in 2:11.03.

When evidence emerged of East Germany’s state-sponsored doping programme, which indicated that as many as 10,000 athletes between 1968 and 1988 may have been taking performance-enhancing drugs, Cierpinski was among those implicated in files uncovered by Werner Franke at the headquarters of the Stasi - the East German secret police.

As a result Shorter advocated for an official review of past performances and suggested medals be stripped from those who were shown to have doped. 

The fourth-placed finisher in the 1976 Olympic marathon, Shorter’s compatriot Don Kardong, also wrote that he believed Cierpinski was involved in the East German doping programme.

Kipchoge won his first Olympic title in Rio by more than a minute, finishing in 2:08:44, with Ethiopia’s Feyisa Lilesa second in 2:09:54 and Galen Rupp of the United States third in a personal best of 2:10:05.

In Sapporo five years later Kipchoge matched Bikila and Cierpinski’s feat of defending the Olympic marathon title as he finished in 2:08:38, with Abdi Nageeye of The Netherlands taking silver in 2:09:58 and bronze going to Belgium’s Bashir Abdi in 2:10:00.

Kipchoge’s attachment to the Berlin Marathon course has been anything but sentimental. Of the last 11 men’s world records in the marathon, nine have been set in the German capital, and the last eight consecutively.

Men's world record-breaking in Berlin began on September 20, 1998 when Brazil's Ronaldo da Costa ran 2:06.05, who also became with that run the first man to run 40km in less than two hours.

Just over a year later Morocco’s Khalid Khannouchi lowered the record to 2:05:42 at the Chicago Marathon, and again, to 2:05:38 at the 2002 London Marathon.

The extraordinary consecutive Berlin sequence began on September 28, 2003 when Kenya’s Paul Tergat became the first man to better 2:05 for the distance, clocking 2:04:55.

Four years later his great track rival, Ethiopia’s Haile Gebrselassie, now his great road rival, lowered the mark to 2:04:26, and again, the following year, to 2:03:59.

There, the mark stood until the 2011 Berlin Marathon, won by Kenya’s Patrick Makau in 2:03:38. Two years later, as discussed, Kipsang bettered the mark with 2:03:23, and the following year another Kenyan, Dennis Kimetto, clocked 2:02:57.

Enter Kipchoge. On September 16, 2018 he won the Berlin race in a staggering 2:01:39. And last year he took a full half a minute off that time.

Variable winds and weather will always have a huge impact upon marathon running. But in trying to establish why Berlin and men’s racing have so often meant world record.

The course is reckoned the quickest of all the six major marathons worldwide - the others being in New York City, Boston, Chicago, London and Tokyo.

The Berlin marathon, traditionally run in autumn and thus more likely to take place in agreeable temperatures, takes place on well-maintained, level roads.

Apart from a small footbridge at the start of the race, the course is very flat - during the course of the marathon there is only 240 feet of elevation.

The race was established in 1974 by Horst Milde, a local baker and runner, and attracted a field of just 244 runners, including 10 women. Last year’s total finishers numbered 34,879.

The original course was limited to West Berlin, but from 1990, after the fall of the Berlin Wall and with the reunification of Germany, entrants were able to run through the Brandenburg Gate into the other half of the city for the first time before looping back round to finish just after passing through the Gate for a second time.

The hiring and deployment of pacemakers has also been exemplary, assisting in the long sequence of records.

One pacemaker - Kenyan Simon Biwott - went above and beyond in the 2000 race. Due to take the field through to the 28-metres mark, the 30-year-old from Eldoret carried on, accompanied only by the faltering Spanish favourite Fabian Roncero, who dropped out after 29km, and fellow Kenyan Jackson Kabiga.

The latter also dropped back and was caught by the fast-finishing Spaniard Antonio Pena, but by then Biwott had a sufficient lead to earn victory in a time of 2:07:42, which earned him around $25,000 (£20,500/€23,500) in prize money, $17,000 (£14,000/€16,000) in bonuses - and, presumably, his fee as pacemaker.

"First I did my job and ran 28k,” Biwott said. 

"This race was a test for me as I had problems with my leg in the Spring earlier this year. I felt fine and carried on. At 35k I knew I had a good chance to win the race."

The Berlin Marathon has also witnessed three women’s world best marks. In 1977, Christa Vahlensieck ran 2:34:48; in 1999 Kenya’s Tegla Loroupe ran 2:20:43 and two years later Japan’s Naoko Takahashi, the Sydney 2000 Olympic champion, set a new mark of 2:19:46.

Kenya’s Gladys Cherono set a Berlin women’s record of 2:18:11 in the 2018 race as she won her third title in the space of four years.

Last year, Ethiopia’s surprise winner Tigist Assefa, lowering her personal best by 18 minutes, won the Berlin title in 2:15:37 - a national record for the former 800m runner that was then the third fastest women’s time ever and is currently the fifth.

After his triumphant performance in Berlin last year Kipchoge had time to hug his trainer, friends, pose for photos, and wave the Kenyan flag before the second-place runner - fellow Kenyan Mark Korir - finished, four minutes and 49 seconds later.

"My legs and my body still feel young," Kipchoge said. "But the most important thing is my mind, and that also feels fresh and young. I'm so happy to break the world record."

Now the multiple champion - whose track career peaked in 2003 when he beat Hicham El Guerrouj and Kenenisa Bekele, no less, to the world 5,000m title - is returning to his maximum comfort zone - if such a term can ever be applied to a marathon venue - with something to prove. Or at least, a doubt to assuage.

In April this year, Kipchoge could only manage sixth place in his first race on the hilly course of the Boston Marathon after suffering with a leg injury and also missing a water break.

So today’s race - the 49th edition - may provide a telling indication of whether his talent is on the wane or whether he is able to return to his previous meteoric trajectory.

Should Kipchoge falter, his compatriot Amos Kipruto, winner of last year’s London Marathon and second-place finisher behind the Olympic champion at the 2018 Berlin Marathon, will be ready to take advantage.

Kipruto, who won world bronze in the crushing conditions of Doha four years ago, has a personal best of 2:03:13, set in finishing second - again to Kipchoge - at last year’s Tokyo Marathon.

Assefa, meanwhile, will defend her Berlin title against a field where her most likely opposition will come from Kenya’s Sheila Chepkirui, who last year won the Berlin Half Marathon and a bronze medal at the Commonwealth Games in Birmingham.

The 32-year-old Kenyan has a personal best of 2:17:29 set in Valencia last year.

But there are other strong contenders from Ethiopia involved in the race, notably the third, fourth and fifth fastest entrants, respectively Tigist Abayechew, who has run 2:18:03, Workenesh Edesa, who has clocked 2:18.51, and Hiwot Gebrekidan, who has a best of 2:19:10.

The aspect of the whole day could change, of course, should climate activists stage protests during the race.

Berlin race organisers have pleaded with the activists not to disrupt the event, although they have admitted they are prepared for "such eventualities", AFP reports.

The German Letzte (Last) Generation climate action group has said it intends to target the race.

"Because there seems to be confusion: yes we will interrupt the Berlin marathon," the group said in a statement. 

"We can't run away from the climate catastrophe."