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Letter from Leiden

Of Cesspits and Sewers

Exploring the unlikely history of sanitation management in medieval Holland

January/February 2019

Leiden Sewers ExcavationOn a balmy July afternoon, archaeologist Roos van Oosten strides through a muddied plot of land near the center of the Dutch city of Leiden and takes an exploratory sniff. The plot, bordered on all sides by apartment buildings, will soon be part of a housing development known as the Meelfabriek, but, for now, van Oosten and a team of excavators from RAAP Archaeological Consultancy are studying the remnants of a 400-year-old neighborhood.


With another sniff, van Oosten gestures to a brick-lined pipe, half obscured with mud. A backhoe rumbles to life and swings its toothed bucket down on the pipe, cracking it open. It is a sewer. Exposed to all present is a stew of squelching, midnight-black muck—excrement that has been brewing for four centuries. Released into the air is an eye-watering aroma, a smell so concentrated and forceful it seems to take shape as a cloud. The excavators stagger back a step, turning their cheeks as though they’ve been slapped. Van Oosten peers down into the muck, and, with a lilt in her voice, says, “Jackpot!” She scribbles notes on a small pad. From her backpack she pulls a laminated map of Leiden showing the layout of the walled city in the mid-seventeenth century. She moves her finger across the map, following the route of the sewer pipe.


Van Oosten is a connoisseur of muck. She has spent the last decade sifting through the cesspits and sewers of medieval European cities, studying how people of the late Middle Ages managed their waste. In society’s relationship to its so-called “foul matter,” she has uncovered surprisingly intimate details of medieval life. In long-overlooked municipal archives on sanitary infrastructure, she has tapped into civic attitudes to dirt and waste. With a latrine’s-eye view of history, van Oosten, along with other scholars, is now challenging the popular vision that the streets of late medieval Leiden—or London, or Paris, or Bruges, or any other sizable city of the time—were dark, gloomy quagmires. In fact, van Oosten says, the humble brick cesspits that characterized urban medieval life in cities such as Leiden were relatively hygienic. It wasn’t until cesspits gave way to sewer-based infrastructure in the early modern era that the relationship between the citizens of Leiden and their waste turned truly foul.


Today, Leiden is a small, placid city of 125,000, where rows of narrow, ivy-covered townhouses line a jigsaw of canals. Situated near the North Sea between The Hague and Amsterdam, it is home to the oldest university in the Netherlands—Leiden University—where researchers have made some of the greatest discoveries of modern science, from the recognition of the Big Bang to the concept of superconductivity. It’s a place that has been featured in documentaries about urban planning and efficient infrastructure, where unhurried cyclists glide back and forth over bridges, and boaters on the canals stop to enjoy dockside picnics.


While the excavators sift through the muck at the Meelfabriek in search of artifacts, van Oosten pedals her bicycle through the streets of the city. As she rides over the cobblestones, she points out vestiges of medieval Leiden that have survived the intervening centuries. Leiden was once a hub of the textile industry, she explains, a place where fabric of all types was processed and then distributed throughout Europe. Down one passage, lining the shaded bank of a canal, were the homes of spinners, weavers, and tuckers, the artisans who manufactured the textiles. Down another street was the Laecken-Halle—the “Cloth Hall”—the guild house of the wool merchants, where fabric was inspected before being put to market. The medieval city, she says, was a bustling place, far denser than it is today, where neighbors were living one on top of the other.



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