HOUNSLOW HEATH AND GUNPOWDER MILLS
Compared to its ancient extent, today’s Hounslow Heath is shrunken indeed! The ancient scale of Hounslow Heath gave it many different purposes over the years. In 1647, during the English Civil War, Oliver Cromwell established a military camp on the heath. From there, Cromwell marched his ‘Model Army’ of 20,000 men on London to overthrow the monarchy. With his success, the monarch, King Charles I was executed and it is rumoured that his body was carried through Hounslow Heath, under the cover of darkness, to its internment at Windsor!

James II Military Camp on Hounslow Heath, 16.000 Troops, 1687.


An officer of the Middlesex Yeomanry in Dress Uniform, c. 1894.
Forty years later, in 1686, King James II established a military camp on Hounslow Heath. Every summer, the entire British Army came to the camp for training and tournaments. During the day, they built earthworks and siege-works, putting on displays where half the army would attack the other half in a mock battle. The camp became something of a tourist attraction, with a market being set up to provide for the many visitors travelling from London and further afield to see the great army at work. Hounslow Heath was so important to the Army that by 1800 they had built a barracks at Hounslow – and it’s still there today!
Hounslow Barracks

Hounslow Barracks Guard Room with hussars, WWII

Hounslow Cavalry Barracks, 1864.
We can thank the British Army for us having some of the heath left at all – much of the original heathland has been covered in housing and Heathrow Airport. However, after the Army had finished using the land for training, the government gave the land to Hounslow Council to make it into a Local Nature Reserve.
General Roy’s first measurement in the survey that started the Ordnance Survey’s mapping of Great Britain was made on Hounslow Heath in the 18th century. He had to make a perfectly straight line that was five miles long so that sightings made from each end could be used to calculate the distance from Hounslow Heath to other landmarks across the country. General Roy and his soldiers marked the ends of the baseline with canon barrels, which can still be seen today. When Roy’s baseline was re-measured by GPS satellite in 1997, they found that the old soldier had done so well that his five-mile line had an error of only ten centimetres over its entire length!
