Water polo has a history that spans roughly four centuries in one form or another. Initially horses were used to play the game, as this Dutch painting shows. The game was a version of modern polo, played on the beach, with high tide signalling the end of the match. This version of the game was phased out early in the eighteenth century, however, as the Dutch chose to reclaim land from the sea and beach space became scarcer: these tracts of reclaimed land were named after the sport in its original Welsh, polo dwr, hence the Dutch polder. Moreover, the tendency to play on until the last possible moment drew criticism from the first animal liberationists, and with good reason:   one account tells of how an entire team of seven horses was lost in a championship final as Utrecht sought a last-minute equaliser against their oldest rivals, the Hague.

The game therefore suffered a major lull in popularity, as what had previously been a sport of kings went underground in a bid to escape unwanted attention. While traditionalists struggled to avoid animal welfare groups, however, another set of pioneers formed a breakaway league that laid the foundations for the game we know and love today.

These founding mothers and fathers had played the original game and had consequently grown used to surviving the drowning horses in what had come to be known as injury time. Their swimming skills had therefore vastly improved, so they decided to put this side-effect to good use. Abandonning the use of horses, though retaining full riding gear, these sportsmen and women created modern waterpolo.

The nineteenth-century saw many changes in the game, notably in the ball; an inflated pig's bladder and later, with the advent of latex, a rubber ball replaced the original puck. For the sake of convenience, most of the riding gear was now abandonned, though the riding helmet was retained to protect against injury.

Water polo's popularity reached its zenith in the second half of the nineteenth century, particularly in France.   The game had generally moved inland to fresh water, and the Seine proved a particularly popular location. Newspapers carried spot the ball competitions for water polo, most of which have since been lost. Some do survive, however, including this picture of a famous encounter between Asnières and La Grenouillère. It is clear from this illustration that the game was a spectator sport, but that on wider rivers one umpire had to resort to skulling to keep up with play (he is just visible in the far right of the picture). Note also that the technology of water polo hats was still somewhat limited, with very little protection for the ears.

The history of water polo remains somewhat contentious, with some advocating a
rather alternative view. Nevertheless, a modern version of the game is now played all over the world.

Great Thanks to Philippe Parker for the above information.
http://www.tokolos.demon.co.uk/polodwr.htm