One bottle, passed between two riders on a mountain, in a photograph that has been argued about for more than seventy years.
The two Italies
In the late 1940s and early 1950s, Italian public life had a convenient shorthand. You were a Coppiano or a Bartaliano.
Bartali was the elder: Tuscan, openly and seriously Catholic, austere, associated with the older and more rural country. Coppi was the younger: Piedmontese, physically odd and technically perfect, associated with modernity, and later with a relationship outside marriage that caused a genuine national scandal.
The rivalry was not manufactured by the press, although the press enjoyed it enormously. The two men genuinely did not get on.
The 1948 World Championship
The clearest evidence of how bad it was. Riding for the same Italian team, each refused to work for the other. Both abandoned the race. Both were suspended by the Italian federation, which had been publicly embarrassed.
The photograph
It was taken at the 1952 Tour de France, on a mountain stage, and it shows Coppi and Bartali alongside each other with a water bottle passing from one hand to the other.
It is the single most reproduced image in Italian cycling.
The argument
The question is simple and unanswerable: who is giving?
Coppi maintained he handed the bottle to Bartali. Bartali maintained he handed it to Coppi. Neither ever conceded. Each told his version for decades and each was believed by his own constituency.
Even the surrounding facts are contested. Accounts differ on the climb, on the stage, and occasionally on the year, partly because similar exchanges were photographed on more than one occasion. There is no definitive resolution and there is unlikely ever to be one.
Why the ambiguity is the point
A photograph that settled the question would be worth much less. What makes this one endure is that it is a picture of cooperation between two men whose entire public identity was built on opposition, and that neither of them would allow the other to be the giver.
Even in the act of sharing water, they were competing over who had shared it.
Why it goes on a wall
Because it is the rarest thing: a genuinely famous sporting image whose meaning has never been fixed, and which two participants spent their lives describing in mutually exclusive terms.
One bottle, and nobody will ever agree.