Once upon a time (well, before 1831), two interesting facts were true: London Bridge was located somewhat further downstream on the Thames than it is now, and a climatic bump in the road called the Little Ice Age (ca. 1300-1900 AD) held most of Europe in its chilly grip.
So what do these facts have to do with each other?
Plenty, as it turns out! These two circumstances resulted in rare but wonderful phenomena known to Londoners as Frost Fairs. Especially hard winters would freeze the Thames hard enough so that it would support foot traffic…and of course, London’s citizens rushed to enjoy the novelty of strolling across the river wherever they chose to, rather than being forced to use bridges or boats…and where curious and excited Londoners thronged, other Londoners determined to make a fast shilling or two followed. Enterprising tradesmen opened stalls on the ice selling everything from warming (or intoxicating!) beverages to food to books and toys, while others opened games stalls, rather like a country fair.
Frost Fairs were recorded in 1564, 1608, 1634, 1715, 1739, and 1789. The last and probably best known Frost Fair happened in February of 1814. A cold and very snowy January gradually closed the Thames’ flow, and by February 1st hardy souls were venturing out onto it. The inevitable crowds followed and within a few days drinks stalls, printing presses selling souvenirs cards with “Printed on the Thames” on them, and stalls selling any other item that could be similarly labeled (and sold for inflated prices!) were doing a brisk business. One stall built a roaring fire and roasted a sheep on it (spectators were charged admission just to watch it cook!) then sold it by the slice as “Lapland mutton”. Swings (see them in the middle right of the picture above?), skittles, merry-go-rounds, donkey rides, and even an elephant added to the festival air.
Of course, a thaw was inevitable. By February 7 the river was once again flowing and the Fair a thing of the past. In 1823 London Bridge was re-built further upstream and in 1831 the old London Bridge torn down, causing the Thames to flow more swiftly, so that it never froze over again.