A cannonball fired more than 500 years ago during the Battle of Barnet was discovered by pupils digging up potatoes in their school allotment.
The find was made by Year 5 pupils at Livingstone Primary in New Barnet when they went to harvest the latest crop at their Baring Road school.
The heavy metal ball was verified by the Barnet Museum as a genuine artefact from the battle, which took place during the War of the Roses in 1471.
Now the relic will form part of a mini-museum being set up at the school later this year to mark its 60th anniversary.
Students made the discovery while gardening in the school allotment, which was restored two years ago as part of a joint project with St James’ Church.
The ten-year-olds said they initially thought they had dug up a very heavy potato, but realised they were on to something when they brushed the mud off to reveal the black, rusted ammunition.
Year 5 pupil Mergim Aliu, aged ten, said: “It was really exciting. It’s not every day you get to hold a cannonball.”
Churchwarden Mike Macey helps organise the allotment project at the school and said the discovery was an unexpected bonus to the educational aspects of gardening.
The children are now putting together an assembly on the Battle of Barnet to show their find to the rest of the school.
Teacher Janie Knappett, who helps organise the project, said: “It is a really exciting opportunity to get the children involved in their local history.”