There is a very short answer to the above question, and a longer one that looks into our relationship with our history, and how outlandish ideas can take root in the public consciousness. We’re pretty sure you can guess the short answer. Here's the long one:
Around 60AD, Boudica wanted vengeance against the Romans who were occupying Britain, after they flogged and raped her and her daughters. She led the Iceni tribe down from East Anglia, razing Colchester and St Albans. Thousands were killed by her army, before it was defeated by a small Roman force. Boudica died after the battle, possibly by poisoning herself, ending the Iceni rebellion. Details of the battle, such as where and when it took place, are sketchy.
Boudica is the only person who has destroyed London and then had a statue raised to her, albeit a good 1800 years later. The Westminster Bridge statue (pictured above) depicts Boudica and her daughters on a chariot. Its creation was overseen by Prince Albert. The statue was to underline Queen Victoria’s power; the names Boudica and Victoria both mean ‘victory’.
Albert briefed the sculptor Thomas Thornycroft on how it should look and lent Thornycroft his own horses as models. Thornycroft died in 1885 before the statue was cast and the project was completed by his son, John Isaac Thornycroft.
John Isaac Thornycroft suggested that the statue should be placed on Boudica’s Mound, also known as Boudica's Grave, on Hampstead Heath, the supposed burial site of the Iceni Queen. However, a couple of brief digs found nothing but domestic rubbish, so the idea was shelved.
There is no evidence that Boudica is buried on Hampstead Heath, but this did not stop the Order of Bards, Ovates and Druids placing a wreath on the mound on the solstice in 1967. Boudica, the druids explained, was cremated, hence the lack of a body in ‘her’ mound.
Another rumoured burial place for Boudica is Peckham Rye. In a report submitted in 1905 after protests against the enclosure of One Tree Hill, councillor John Nesbet couldn’t resist wandering around the nearby Rye and imagining it as the site of the Iceni’s last stand. He wrote of
a Roman wedged charge like a whirlwind through the serried enemy [...] sweeping all before on to the more level Peckham Rye.
How the rebel chariots made it across the first century Thames was not considered.
The most famous possible site for Boudica’s grave is under the platforms at King’s Cross station. This idea began with John Bagford and a dead elephant. The elephant was discovered near a flint axe head in a gravel pit at the top of Gray’s Inn Road.
In 1715, Bagford published a suggestion that the elephant has been brought over by the Romans, and that the flint was a spearhead of a British warrior who fought them.
John Nelson's History of Islington, published in 1811, contains the first known suggestion that the area is known as Battle Bridge because of Boudica’s last battle against the Romans. Nelson also suggests that the remains of Barnsbury Manor was a Roman camp, and by 1835 it was marked as Roman on a map of Islington.
The problems with all of these ideas is that they are all false. Barnsbury Manor’s remains were medieval. The dead elephant and the ‘spear head’, actually an axe head, were neolithic. Battle Bridge is not named as a site of a battle but is corruption of older names for the area: Bradford, Bradford Bridge and Batford Bridge. It was not known as Battle Bridge until 1600 years after Boudica.
This didn't stop former Scotsman editor Lewis Spence from peddling these incorrect ideas as fact in his 1937 book Boadicea: Warrior Queen of the Britons. He drew on all of the speculation above, referring to it as local tradition, and even plotted a map of the Roman side of the battle. Spence had previously written two ‘factual’ books about the mythical continent of Atlantis.
What Spence did not write about is where Boudica could possibly be buried. There is some speculation that the story of her being beneath King's Cross station first arose during the second world war. Perhaps the presence of a British monarch who mercilessly slaughtered continental invaders helped troubled wartime Londoners.
John Clark, Curator Emeritus at the Museum of London, whose notes have been invaluable to writing this, states that he only heard of the King’s Cross idea in the 1970s. Platform 10 was often given as the specific location. This platform is the end of the train line up to Cambridge — Boudica’s home in East Anglia. For this reason, Clark assumed that the platform 10 rumour was a joke, and it is a joke that has persisted.
In 2008 The Daily Telegraph gave the location as platform 8. The May 2014 issue of BBC History magazine asked Is Boudica buried at Platform 9¾? The article has now been taken down, but myths are promiscuous things, blending with others to continue to be attractive and relevant. Here the fresh-faced Harry Potter mythos has blended with old Queen Boudica.
BBC History should have asked Potter author J.K. Rowling; in 2015 she blogged that she did not know about the myth when she gave the wizard’s platform as 9¾. In truth, platform 9¾ is at King’s Cross because Rowling is Scottish and this is where the trains from Scotland arrive in London. She describes the Boudica tale as ‘suspiciously vague’.
The whole King's Cross idea is vague. It has been rustled up from a misinterpreted place name, and an elephant skeleton. It has, over the last two hundred years, grown a story that has planted a lost, ancient queen under a central London train station. No none knows where Boudica’s bones are, if they are still somewhere at all.
What the tale of Boudica’s grave tells us more of is of those with a yearning to be near to Britain's warrior queen. These include Elizabethans with a female monarch fearing the Spanish armada, Victorians establishing their superiority during their own imperial period, suffragettes looking to a woman who stood furiously for herself against male rulers, and freedom loving 1960s druids commemorating a queen that fought oppression.
The story of Boudica’s grave is not a history but a myth-story — a myth made mystery. When the willing gaze into it they see only what they need.