In 1861, life went on as normal in Victorian Britain. The rich were rich, the poor were poor, and iron railings around houses were many colours: green, red, occasionally black.

By the end of 1862, things had changed. Prince Albert, the Queen's husband, was dead, and the British Empire was plunged into mourning. Victoria wore black, ordinary people wore black, and everyone painted the iron railings around their houses black.

Victoria died in 1901, still in mourning. Although the ordinary British people hadn't been wearing black along with her for the 39 intervening years, their fence rails had. All those freshly painted rails hadn't needed recoating for a long time, and by the time they did, no other colour looked right. An entire generation grew up seeing nothing else .

Then came the World Wars. Railings were torn up and melted into munitions, not to be replaced for years. When they were put back, the only colour anyone could conceive of painting them

So now, throughout Britain, even modern railings still commemorate the death of Prince Albert.