In the shadow of the Shard at the southern end of London Bridge, there’s a curious looking grey spike sculpture jutting up in the sky. Skater boarders use the pedestal for performing tricks, while most people probably simply walk past it. But this feature has a great deal of historical significance as it commemorates a dark period of over 300 years when alleged traitors’ heads were put on spikes for all to see. Their presence served as a warning to anyone thinking of challenging the Crown. And at the same time they became a tourist attraction, attracting visitors from far and wide.

Running through the names of the heads’ owners is like being given an A to Z list of the biggest accused traitors of medieval England. Once put on the spike on one of the gates at the ends of London Bridge, they were left to the elements to rot and eventually fell in the Thames.

William Wallace, the first to fall to this fate in 1305, was a Scot who was found guilty of leading a campaign against Edward I. Jack Cade in 1450 led a rebel army but failed to overthrow the government so his head was put up on London Bridge for all to see. His attempt was crushed because he lost the support of the people, after having raped many of the locals in the City.

Later came Thomas More who refused to accept Henry VIII as supreme head (no pun intended!) of the Church of England. Then Guy Fawkes’ head made the stake after the Gun Powder plot of 1605. And when the King was restored after Cromwell’s reign, some of those who had signed the death warrant of Charles I also suffered this chilling fate.

Back then it was a different London Bridge, the stone medieval construction with its shops, houses and chapel, a few metres down-stream from today’s structure, but it is chilling history all the same. The heads were first displayed on Drawbridge Gate, at the northern end, and then later on Stone Gate, at the Southern End. In 1592, 34 displayed heads were counted by a German visitor on London Bridge.

For London Bridge, the practice was ended in 1678 when the heads of the most important traitors started to be displayed at Temple Bar instead. Today, the appalling London Bridge Experience ‘tourist attraction’ on the southern side of London Bridge tries in its own tacky way to bring the gruesome tradition of displaying heads ‘to life’. But perhaps the assuming grey sculpture is a more fitting memorial.