The London Clay Foundation
The geological formation that underlies Highgate is, in many respects, the foundation of its entire history. The London Clay, a thick deposit of marine sediment laid down some fifty million years ago when a warm, shallow sea covered what is now south-east England, forms the bulk of the Highgate ridge. This dense, blue-grey material, rich in iron compounds and organic matter, is one of the most extensive and accessible clay deposits in Britain. It has been used for brick-making since at least the Roman period, when the legions established tileworks along the Thames and at various points inland. The clay's particular virtue for the brick-maker is its consistency and its plasticity — when mixed with the right proportion of water, it can be moulded into shape and, when fired at a sufficiently high temperature, it produces a hard, durable brick of distinctive yellowish-brown colour.
The Highgate ridge offered an especially convenient source of this material. The clay was exposed on the hillside slopes, where erosion and the cutting of roads and tracks had revealed thick beds of workable material. The overlying Bagshot Sand and Claygate Beds, which cap the hilltop, were relatively thin and easily stripped away to reach the clay beneath. And the topography of the ridge itself was advantageous: the slopes provided natural drainage for the brickfields, and the hilltop position meant that the kilns' smoke — a significant nuisance in an era before any concept of air quality regulation — was carried away by the prevailing winds rather than settling on the immediate neighbourhood.
The chemistry of the London Clay varies across its extent, and the Highgate deposits had their own particular characteristics. The clay here contained a relatively high proportion of calcium carbonate — lime — which acted as a natural flux during firing, reducing the temperature needed to vitrify the brick and producing a lighter, more yellowish colour than the deep red bricks produced from clays with higher iron content. This Highgate stock brick, as it came to be known, was well suited to the construction of the Georgian and early Victorian houses that would eventually replace the brickfields themselves.
Medieval Origins of the Industry
The earliest brick-making in the Highgate area is difficult to date with precision. Brick was used in English construction from the late medieval period, initially as an imported luxury material and then, from the fifteenth century onward, as a locally produced building material that gradually supplanted timber and stone in areas where neither was readily available. The heavy clay soils around Highgate would have been recognised as a potential source of brick clay from an early date, and it is likely that small-scale, seasonal brick-making was practised on the hillside long before any formal brickfield was established.
The first documented references to brick-making in the Highgate area date from the sixteenth century, when the expansion of London and the rebuilding that followed the dissolution of the monasteries created a surge in demand for building materials. The Bishop of London, whose manor of Hornsey encompassed much of the Highgate ridge, granted licenses for clay extraction on his lands, and small brickfields appeared on the slopes below the village. These were modest operations — a pit, a mixing area, a row of drying sheds, and a clamp or temporary kiln — operated by a handful of men during the dry months of summer and autumn when the clay could be dug and the bricks dried before firing.
The Great Fire of London in 1666 transformed the brick-making industry across the capital's hinterland. The rebuilding acts that followed the fire specified that new buildings in the city should be constructed of brick or stone, creating an enormous and sustained demand for bricks. The Highgate brickfields, conveniently situated on the main road north out of London, expanded rapidly in the decades after the fire. New pits were opened, permanent kilns were built, and the industry became a year-round operation employing dozens of men, women, and children. The bricks that rebuilt London after the Great Fire came from many sources, but the Highgate kilns, with their accessible clay and their proximity to the city, were among the most important suppliers.
The Kiln Sites of N6
By the eighteenth century, the brickfields of Highgate occupied a significant area on the lower slopes of the ridge, particularly on the western side facing Dartmouth Park and the eastern side toward Hornsey. The principal kiln sites can be identified from contemporary maps and from the archaeological evidence that periodically emerges when houses in the area undergo renovation or rebuilding. The most extensive brickfield lay in the area now bounded by Dartmouth Park Hill, Highgate West Hill, and the southern end of the village. This site, which operated from at least the early eighteenth century until the 1840s, covered several acres and included multiple kilns, drying sheds, clay pits, and workers' cottages.
A second major brickfield occupied land on the eastern slope of the ridge, in the area between Archway Road and what is now Jackson's Lane. This site took advantage of the thick clay deposits exposed by the natural erosion of the hillside, and its products were carried down to London by horse and cart along the Archway Road. A third cluster of kilns operated in the area around what is now Cholmeley Park, where the clay was of particularly good quality and where the brick-makers had the additional advantage of a nearby supply of sand for mortar-making from the Bagshot deposits on the hilltop.
The physical arrangement of a Highgate brickfield followed a standard pattern. At the centre was the kiln itself — a rectangular or circular structure of firebrick, open at the top, in which the raw bricks were stacked and fired. Around the kiln stood the drying sheds, long, low structures with slatted walls that allowed air to circulate around the unfired bricks as they dried. The clay pit, which grew deeper and wider as material was extracted, was typically at one end of the site, and a horse-powered pugmill — a device for mixing and kneading the clay — stood between the pit and the moulding benches where the bricks were shaped. The whole operation was messy, smoky, and labour-intensive, and it dominated the landscape in which it sat.
The Labour of Brick-Making
The workforce of a Highgate brickfield was hierarchical and specialised. At the top of the hierarchy stood the brick-maker himself — the master craftsman who mixed the clay, judged its consistency, and supervised the firing. Below him were the moulders, who pressed the prepared clay into wooden moulds to form individual bricks; the off-bearers, who carried the moulded bricks to the drying sheds; the burners, who tended the kilns during the firing process; and the labourers who dug the clay, hauled the fuel, and loaded the finished bricks onto carts. Women and children were employed extensively in the lighter tasks — carrying bricks, turning them during drying, and sorting the fired bricks by quality.
The work was physically demanding and carried significant health risks. The clay diggers worked in wet, cold conditions for much of the year, and the heavy lifting involved in extracting and transporting the raw material took a toll on backs, shoulders, and joints. The moulders, who worked at a furious pace to produce their daily quota of bricks, suffered from repetitive strain injuries and from the effects of constant contact with wet clay, which dried and cracked the skin of their hands. The kiln workers faced the most acute danger: the heat of the firing process, which raised the temperature inside the kiln to over a thousand degrees, created a risk of burns and heat exhaustion, while the smoke and fumes from the burning fuel — typically coal, supplemented with wood and sometimes household refuse — caused respiratory problems that shortened lives.
The wages paid to brickfield workers in the Highgate area can be traced through parish records and occasional legal documents. In the early eighteenth century, a skilled moulder could earn around two shillings a day — roughly comparable to a carpenter or mason — while labourers earned perhaps half that amount. Women and children were paid still less, typically by the piece rather than the day. These wages were sufficient to support a modest existence in the cottages that clustered around the brickfields, but they offered no security against illness, injury, or the seasonal fluctuations that affected the industry. In winter, when wet weather made brick-making impossible, many workers were laid off and forced to seek poor relief from the parish.
The Product and Its Market
The bricks produced at Highgate were of several grades and types, each suited to different uses and commanding different prices. The finest were the facing bricks — well-shaped, evenly coloured, and free from cracks or distortions — which were used for the visible exterior walls of buildings. These were typically the bricks from the centre of the kiln, where the heat was most evenly distributed and the firing most thorough. Slightly inferior bricks, perhaps unevenly coloured or slightly misshapen, were sold as seconds and used for internal walls, party walls, and other locations where appearance was less important than structural integrity. The poorest bricks — those that had been overfired and distorted, or underfired and soft — were broken up and used as rubble fill or aggregate.
The market for Highgate bricks was overwhelmingly London. The capital's insatiable demand for building material, driven by continuous population growth and the periodic destruction of fire and redevelopment, ensured a steady market for any brick-maker within cartage distance of the city. The Highgate kilns had the advantage of being situated on or near the main road from London to the north, and their products could be delivered to building sites in the city within a few hours. The characteristic yellowish stock brick of the Highgate kilns can be seen in houses and commercial buildings across north London, from the terraces of Tufnell Park to the warehouses of King's Cross.
The brick-makers of Highgate also supplied a more local market. As the village grew during the eighteenth and early nineteenth centuries, the houses that were built on the former common land and along the new roads of the expanding settlement were constructed from bricks made on the spot — or very nearly so. There is a satisfying circularity in the knowledge that many of the elegant Georgian houses that line Highgate High Street and The Grove were built from clay extracted from the fields just below them, shaped and fired within sight of the building plots, and carried uphill by the same labourers who had dug the clay in the first place.
Decline of the Brickfields
The decline of brick-making in Highgate was driven not by any failure of the industry itself but by the rising value of the land on which it operated. As London expanded northward during the first half of the nineteenth century, the fields and commons around Highgate became increasingly attractive to speculative builders. Land that had been worth a few pounds per acre as agricultural ground or brickfield became worth hundreds of pounds per acre as building plots. The brick-makers, who typically leased their land rather than owning it, found their leases terminated and their operations displaced as landlords chose to sell to developers rather than continue to collect modest rents from industrial tenants.
The process was gradual but inexorable. The brickfield on Dartmouth Park Hill was closed in the 1830s and its site developed for housing within a decade. The kilns on the eastern slope were displaced by the construction of the Archway Road improvement in the 1820s and the subsequent development of the surrounding area. The Cholmeley Park site survived somewhat longer, partly because its owner was reluctant to sell and partly because the quality of its clay continued to command a premium price. But by the 1860s, even this last significant brickfield had closed, its kilns demolished and its pits filled in to create the level building plots on which the Victorian terraces of the area now stand.
The final blow to local brick-making was the arrival of the railway. The same railway network that connected Highgate to London also connected London to the enormous brickfields of the Midlands — the Bedfordshire and Buckinghamshire clay pits that could produce bricks in vast quantities at lower cost than any London kiln. The Fletton brick, named after the village near Peterborough where the process was perfected, could be made cheaply from the Oxford Clay and transported to London by rail at a fraction of the cost of local production. Against this industrial competition, the small-scale Highgate kilns had no chance.
Traces in the Modern Landscape
The brickfields of Highgate have left their mark on the landscape in ways both obvious and subtle. The most visible legacy is the ground itself. Areas that were quarried for clay remain slightly lower than the surrounding terrain, and the filled pits, though now covered with houses and gardens, occasionally reveal their origins when foundations are dug or drainage problems arise. Builders working in the Dartmouth Park and Highgate West Hill areas have reported encountering layers of ash, clinker, and broken brick — the debris of the kilns — beneath the topsoil, sometimes at surprising depths. These industrial deposits are a reminder that the neat Victorian terraces above them stand on ground that was, within living memory of their first occupants, a working industrial landscape.
Street names offer another clue to the vanished industry. Brick Lane, which runs between Highgate and Hornsey, is an obvious reference, though its name may predate the formal brickfields and refer instead to an older, less organised tradition of clay extraction. The names of fields and parcels of land recorded on eighteenth-century maps — Brick Field, Kiln Close, Clay Pit Meadow — survive in some cases as the names of modern properties or as boundaries in the Land Registry records, though they have been largely forgotten by current residents.
Perhaps the most enduring legacy of the Highgate brickfields is the material itself. The bricks that were made on the hillside in the seventeenth, eighteenth, and nineteenth centuries are still in place in the walls of thousands of buildings across north London. They can be identified by their characteristic colour — a warm, yellowish-brown that darkens to grey where soot has accumulated — and by their slightly irregular shape, which distinguishes handmade bricks from the machine-pressed products that replaced them. Every house in Highgate built before about 1860 contains bricks that may well have been made from clay dug within a mile of the building site. The village, in a very literal sense, was built from itself.
An Industry Forgotten
The brick-making industry of Highgate has been almost entirely forgotten. No kiln survives, no brickfield is preserved, and no museum or heritage centre tells the story of the men and women who dug the clay, moulded the bricks, and tended the fires that produced the building material of a city. This amnesia is not unique to Highgate — the story of brick-making has been neglected across London, overshadowed by the more dramatic narratives of trade, politics, and culture. But the brick-makers of Highgate deserve to be remembered, not least because their labour created the physical fabric of the neighbourhood that has so completely erased their memory.
The transformation from industrial landscape to residential suburb happened within a single generation. A man born in the 1820s, who had worked as a boy in the Highgate brickfields, could have lived to see the same land covered with neat terraces of houses built from bricks identical to those he had once helped to make. The speed of the change was astonishing, and it was replicated across London's expanding fringe. But in Highgate, the irony was particularly pointed: the industry that had supplied the raw material for the village's growth was itself consumed by that growth, its sites buried beneath the very houses it had helped to build.
To walk through the streets of Highgate today, past the handsome brick facades of the Georgian and Victorian houses, is to walk through a landscape shaped by an industry that has vanished so completely that most residents are unaware it ever existed. The bricks in the walls are the only monument to the brick-makers of N6 — a monument that is at once ubiquitous and invisible, present in every street and seen by no one. It is a fitting legacy for an industry that was always more concerned with producing a useful material than with recording its own history, and it serves as a reminder that the most fundamental elements of our built environment are also the most easily taken for granted.
*Published in the Hampstead Renovations Heritage Collection — exploring the architecture, history, and stories of London's most remarkable neighbourhoods.*