Alas, 150 years after his birth on January 1, 1863, and hard on the heels of the centenary of the sport he invented 25 years later there is again a real and present danger that it may be booted out of the Olympic Games.
The International Olympic Committee's (IOC) Programme Commission meets shortly to make recommendations to the Executive Board, with a final decision to be made at the September congress in Buenos Aires on whether a possible two new sports should be included in the 25 core elements for the 2020 Games.
The contenders are karate, wushu, roller sports, sport (indoor) climbing, squash, wakeboard and baseball/softball.
This could mean that one, maybe two, of those we enjoyed in London will, disappear from the programme. Modern pentathlon is believed to be high on the list of the vulnerable.
Squash, in my view has the strongest case to come in (surely it has more right be there than tennis) but not at the expense of dear old mod pen.
It would be a travesty if Coubertin's baby was thrown out with the bath water.
For me, the sport has always been a reminder of a gentler, more romantic era before the pursuit of sporting glory became suffused by greed, drugs, duplicity and mind-numbing reality television.
Ah yes, the great god TV. There was once an argument that modern pentathlon was unsuitable for the box. But to help make it more televisual, what was once a five-day test of strength, skill and endurance via running, shooting, fencing, swimming and riding has been successfully compressed into one, played out between dawn and dusk.
In London, mod pen also pioneered laser shooting ahead of other gun disciplines, which controversially still employ real bullets.
Despite these innovations, and others now revealed on insidethegames, plus the growing popularity of the sport among emerging nations, apparently there are those on the IOC who sniffily perceive the modern pentathlon as old fashioned, and there little doubt that its continued presence is threatened as, I believe is taekwondo should karate be brought into the 2020 programme.
Even worse, if modern pentathlon should even be considered expendable for the likes of the Oriental martial art of wushu (which sounds like a character in Aladdin), or clambering up the walls of a gymnasium.
First introduced at the Stockholm Games of 1912 by the bold Baron, it is something at which Britain has done particularly well at Olympic and World Championship level, as reflected in UK Sport's 11 per cent increase of its funding through to Rio 2016.
GB is well represented internationally, too. Martin Dawe, a former competitor and team manager, now vice-chair of Pentathlon GB, is an Executive Board member of the International Modern Pentathlon Union (UIPM), the global governing body. He is not alone in underscoring the supreme irony of the threat to the sport when the Olympics are celebrating the anniversary of its, and the entire Movement's, founder.
He points out that that it is no longer largely the preserve of Eastern Europe having spread across all continents, notably to Asia and South America.
In order to further boost its popularity UIPM has a run-swim biathlon event and with the advent of laser shooting there is the planned competitive option of a triathlon (run-swim-shoot) which could appeal to Third World nations.
UIPM also introduced a successful mixed relay event (male and female) in the last Youth Olympics.
Now there are plans to stage the entire Olympic event in one existing stadium, which would, include a temporary pool, as early as Rio. It would take place over five hours for the price of a single ticket.
Is that "modern" enough for the IOC?
Another who hopes so is Jim Fox, who led the British men's team to gold in the Montreal Olympics back in 1976.
Fearing that his sport may go to the wall, he has joined the fight to preserve its status.
Foxy, OBE, once led the charge down sport's superhighway, a swashbuckling, Corinthian hero in an age when sportsmen were exactly that.
They called him the dashing white sergeant. Now, at 71, the old soldier who was, arguably, Britain's outstanding all-round sportsman is a victim of Parkinson's Disease but he continues to battle on two fronts - for his own health and that of the sport with which he became identified.
Fox competed in four Olympics, winning a gold medal with the British modern pentathlon team in the 1976 Montreal Games, a bronze in the World Championships in Mexico and was 10 times national champion.
A fencing master who literally foiled the Soviet cheat Boris Onishchenko in Montreal, he was also a prolific cross-country runner, swimmer, marksman and horseman.
Which made it all the more tragic that such a sporting superman should have been struck down 17 years ago by an illness which attacks muscles and mobility – the same crippling condition that affects his famous namesake, the actor Michael J Fox and his even more celebrated sporting contemporary from the seventies, Muhammad Ali.
Like them, Fox now faces his toughest battle, a situation he does not shy away from.
There is no skirting delicately around the subject. He always tells people, up front, what's wrong with him. "I don't want them to think I'm pissed," he laughs.
In Fox's case, the fact that he spurned self-pity for a vigorous, reborn self-belief has been spurred by the incentive to fight for the preservation of a pursuit that brought him so much fulfilment.
In a sporting world so disfigured by excess, Fox is well aware that knows the modern pentathlon is regarded something of an anachronism.
Even in his heyday, the modern pentathlon was perceived as being something practised in formation dancing.
But he is angered by the real possibility that the ultimate test for any Olympian could be replaced on the Olympic stage by "Mickey mouse sports."
"It is a disgrace that this should even be considered, an insult to Baron de Coubertin," he told insidethegames. "The modern pentathlon has always been the very essence of what the Games should be about.
"What I will say is that improvements need to be made to the riding event, the horses should be better, and some of the competitors ride like clowns.
"But it makes me very sad to think the sport could be evicted. This must not happen."
Some years back, the IOC President, Juan Antonio Samaranch, suggested to a German newspaper the sport's days were numbered. Fox fired off a furious salvo to Lausanne. It is believed that the Princess Royal, a fellow competitor in Montreal, also inserted a flea in the Presidential ear. A swift retraction followed.
A further irony that dad's lad Juan Antonio Samaranch junior, a current IOC member, is a vice-president of UIPM, so at least there is some internal support.
Fox hopes the sport in which Britain has always had such a great tradition can entice more youngsters of both sexes. For the record, these are GB's Olympic medallists:
Montreal 1976: Men's team. Gold, Adrian Parker, Danny Nightingale, Jim Fox.
Seoul 1988: Men's team. Bronze, Dominic Mahony, Richard Phelps, Graham Brookhouse.
Sydney 2000: Women's individual. Gold. Steph Cook. Bronze, Kate Allenby.
Athens 2004: Women's individual: Bronze, Georgina Harland.
Beijing 2008: Women's individual: Silver, Heather Fell.
London 2012: Women's individual. Silver, Samantha Murray.
For those who would like to join the "Keep Mod Pen" campaign I recommend a browse through Modern Pentathlon, A Centenary History, penned by Andy Archibald, who was a reserve in Fox's winning class of '72. Published by Grosvenor House, it is now available on Amazon.
His final chapter concludes: "Nobody who knows anything about the modern sport can ever accuse modern pentathlon of being anachronistic. Every such charge against us has been patiently remedied and modern pentathlon remains in every way the most searching test of the sporting all-rounder."
Here here! If the IOC decides in September that it no longer wants modern pentathlon then the Olympics really will have lost their soul. Or rather, sold it.
Alan Hubbard is an award-winning sports columnist for The Independent on Sunday, and a former sports editor of The Observer. He has covered a total of 16 Summer and Winter Olympics, 10 Commonwealth Games, several football World Cups and world title fights from Atlanta to Zaire.