The stone will commemorate the bicentenary of a unique sports institution: rowing’s Leander Club.

The location is where the old Searle & Sons boathouse once stood. But the story of how a gentlemen’s agreement struck here, in the year of Karl Marx’s birth, led eventually to development of an institution that might be likened to the Manchester United and MCC of its sport rolled into one is by no means straightforward.

According to a new history of the club*, Leander was the name of a vessel called a cutter that was owned by Searle & Sons. In an age when boat races, usually involving some of the watermen who were a critical component of the Georgian economy, were plentiful and gambling an obsession, such craft started to be leased to groups of young gentlemen who had money staked on particular contests.

Since you could not keep up with a race from the shore, this was a way of enabling a few privileged spectators to keep a close watch on the action. In horse sport, steeplechasing managed the same feat for all spectators by introducing circular tracks. But of course, re-routing the Thames was not an option.

As the new book notes, “The particular group organised around 1818 to man the six-oared cutter Leander…was by no means the first”. As luck would have it, however, the legacy of this group has proved by far the most enduring.

If you are going to row fast enough to keep up with a race, you might as well race yourself, and the book goes on to relate how, as rowing gained purchase as a leisure activity, “by the late 1820s many of the most respected and competitive gentlemen amateurs were Leander men”.

As the sport continued to assert its grip beyond the working classes, and as more than a vehicle for gambling, the first Oxford versus Cambridge university boat race took place in 1829 and the first Henley Grand Regatta ten years later.

By this time, London’s frenetic and inexorable expansion (and the accompanying river traffic and pollution) had started to push rowing’s epicentre upriver. By the 1860s, Leander’s base had shifted to Putney and before the end of the century – in 1896, a year with particular resonance for Olympic fans - it started work on the clubhouse in Henley where it is still located today.

For much of its existence, as it grew into a sports club in the sense that we would recognise today, Leander has measured success in terms of its performance at two major events – Henley and the Olympic Games.

It did not enter a crew in that inaugural Henley event in 1839, although the regatta was umpired by a Leander man, on horseback. A year later, the club took the Grand Challenge Cup for the first time.

Since then, while there have been ups and downs, a further 198 titles have been added. So, as press and publicity man Robert Treharne Jones explains during a tour of the clubhouse, there is “a good chance” that the club’s 200^th year will yield its 200^th Henley trophy.

The club had to wait until 1908 to notch its first Olympic medal. Then, with the regatta held on home water at Henley, Leander crews secured two gold and two silver medals.

The eights final, pitting a Leander boat against an outstanding Belgian crew, turned out to be one of the stand-out events of the entire Games.

In a contest witnessed by Baron Pierre de Coubertin from the umpire’s launch, a Leander crew considered England’s best, which had “trained hard for several months beforehand”, won by two lengths.

The Official London 1908 Olympic Report leaves one in no doubt as to the perceived significance of the outcome.

The result, it claimed, “finally settled the question of styles that has agitated the English world of rowing for over three years.

“If the Belgians had won…we should have been obliged to reconsider, if not to change entirely, all those principles of oarsmanship on which the crews of Eton and Radley, of Oxford and Cambridge, and of the great metropolitan clubs had founded their tuition.

“For, if Leander had been beaten, there would have been no doubt whatever about the real superiority of the Belgian style. But Leander won in such fast time and by so decisive a margin, that every hesitation has been set at rest.”

Besides their (pure) gold medals and Olympic diplomas, the champion eight were said to have received a “statuette of Pallas Athene”, presented by Comte Brunetta d’Usseaux, an International Olympic Committee member from Italy.

In recent times, of course, Britain has emerged as an Olympic rowing superpower, with Leander’s tally of individual medals rising to a remarkable 124, plus three Paralympic medals.

Much of this recent success may, moreover, be laid at the door of Jürgen Grobler, the former East German coach recruited as Leander’s director of rowing in 1991, in the wake of the Berlin Wall’s destruction.

Four of Steve Redgrave’s five Olympic gold medals, between 1984 and 2000, were won as a Leander member. These included the victory with Matthew Pinsent in the coxless pairs in Atlanta that turned out to be Britain’s only gold medal of the 1996 Games.

Rather like Henley Royal Regatta itself, Leander contrives not altogether successfully to disguise some very modern attitudes towards performance and marketing beneath a quintessentially traditional English surface.

Downstairs from the immaculate clubhouse bedrooms and drawing rooms – it is possible for members of the public to stay the night there, cocooned in rowing history – is a well-equipped gym, complete with pounding music and displayed instructions to “Follow us on Twitter @Leander_Club”.

There is also an athletes’ dining area, where rowers can load up on calories and a dorm, used for resting between workouts, rather than overnight.

The boat-shed houses mainly primrose yellow carbon fibre-reinforced plastic Empacher shells. “We only keep them for three or four years because they begin to lose their stiffness,” Treharne Jones observes, noting that a customised eight, built to Leander requirements, might run to £45-50,000 ($62-66,000/€53-57,000).

He tells me that the club’s annual budget is around £1.5 million ($2 million/€1.7 million), of which about one-third is earmarked for the rowing programme.

“We recruit athletes from all over the country because they know their best chance of getting into the GB squad is to get a place here,” he says. While other clubs produce one or two Olympians, he adds, “we produce them in fistfuls”. The Leander book states that in 2017 fully 63 per cent of the GB senior team were club members.

A few men’s sports teams have sought to stand out and prosper in recent years through an association with girly pink. These include the Paris rugby club Stade Français and latterly the Scotland football team.

“In communications, it is always by trying something different that you attract attention,” Max Guazzini, the then Stade Français President told me a few years ago, when I asked him about this and other eye-catching marketing initiatives. He also confided that the club’s pink away strip accounted at the time for 70 per cent of replica kit sales.

Leander has been associated with the colour for considerably longer than these Jean-come-latelys to pink power, even if no-one seems to be able to quite put their finger on how or why the change from the not dissimilar, but distinctly darker, original club colour of cerise was effected.

The association needs also to be seen in the context of a rowing, and in particular a Henley, scene in which gaudy blazers are a cherished – and, to the initiated, a distinctly useful - tradition.

Even so, I have the impression that Leander has become as adept as anyone at utilising this aspect of its enviably strong club identity to drum up merchandising and marketing income to supplement the money paid in dues by its 3.500 members worldwide.

The club also demonstrably makes the most of its equally strong (and equally mysterious) connection with the hippopotamus, literally “river horse”.

“Upstairs. To your left for the drinks, to your right for the hippos,” was the memorable instruction to new arrivals at a recent bicentenary reception at Henley’s River & Rowing Museum.

It turned out to be a reference to a display of 200 brightly-decorated model hippos. These are being auctioned to raise money for the Kafue River & Rowing Centre in Zambia.

The club was frankly slow off the mark with regard to gender equality, permitting women to become full members only in 1998. “Ultimately it was the National Lottery that changed everything,” asserts the new history, explaining how a £1.5 million ($2 million/€1.7 million) Sports Council grant to help fund a major refurbishment came with “one overriding caveat” – open membership.

It took only a further 15 years for double Olympic silver medallist Debbie Flood to be elected Leander’s first female Captain.

Another Olympic silver medallist, Vicky Thornley, has now followed in Flood’s wake. When questioned, she says that the club has “moved very quickly” on the gender front in the past 20 years.

Thornley describes Leander as “like a second home”. That strikes me as a very good encapsulation of what the best sports clubs can aspire to be.

* Leander Club – the first 200 years.