The History of the Toilet: From Ancient Sewers to Modern Sanitation

In the summer of 1858, members of the British Parliament had to hang lime-soaked curtains over their chamber windows to endure the stench rising from the Thames. This humiliating episode in the heart of the world’s most powerful empire demonstrated, in the starkest possible terms, that how humans handle their own waste is not a matter of mere convenience but a question on which the survival of cities hinges. Here is the surprising part: roughly 4,400 years before this crisis, the city of Mohenjo-daro in present-day Pakistan already had flush toilets in individual homes connected to a functioning public sewer system.

The First Toilets: Sanitation Systems of the Ancient World

Mesopotamia: A Sewage System from 4000 BCE

The oldest traces of sanitation infrastructure in human history were found in Mesopotamia, the region corresponding to present-day Iraq. Archaeological evidence shows that around 4000 BCE, clay drainage pipes were installed at the Bel Temple in Nippur and at Eshnunna.^[1] These pipes were built to handle wastewater and collect rainwater, demonstrating that urban planners of the era already understood the necessity of waste management.

By around 2500 BCE, the Assyrian and Babylonian empires had developed even more sophisticated water supply and sewage systems. Some homes were fitted with primitive toilet structures connected to brick-built drains, and a method of flushing waste into sewers using water was already in use.^[1]

The Indus Valley Civilization: The World’s First Urban Sanitation System

Yet the civilization that possessed the most remarkable sanitation system in the ancient world stands apart. It was the Indus Valley Civilization, which flourished around 2600 BCE — particularly Mohenjo-daro in present-day Pakistan and Dholavira in the Gujarat region of India.^[2]

Archaeologists who excavated the residential quarters of Mohenjo-daro were astonished. Most homes were equipped with dedicated bathrooms and flush toilets. Pouring water into the toilet hole sent waste flowing through clay-brick pipes into a communal sewer system that ran beneath the entire city.^[2] These sewers were covered to allow inspection and cleaning, and records suggest that public sanitation facilities were also provided for those too poor to access private toilets. Scholars have assessed this system as comparable to Rome’s sanitation infrastructure, which would not appear until approximately 2,000 years later.

Ancient Rome: Public Latrines and the Cloaca Maxima

Roman civilization elevated sanitation infrastructure to an entirely new level. The Cloaca Maxima, whose construction began in the 6th century BCE, was a large-scale drainage system built to handle Rome’s urban runoff — and remarkably, it still functions today, draining rainwater from the Roman Forum.^[3]

At the height of the Roman Empire, public toilets known as foricae were installed throughout the city. These facilities, which began appearing from the 2nd century BCE, consisted of rows of marble or stone seats. Unlike modern toilet stalls, there were no partitions; instead, a channel connected to the sewer ran beneath the seats. Water from nearby bathhouses flowed through this channel, naturally acting as a flush mechanism.^[3]

Roman public latrines were more than mere sanitation facilities — they were social spaces. It was commonplace to discuss politics and business while seated side by side. Usage fees from public latrines also served as a source of imperial revenue. Urine was even sold to textile factories for use in processing wool. It was in this context that Roman Emperor Vespasian, upon introducing a urine tax, gave rise to the saying “Money has no smell” (Pecunia non olet).^[3]

The Medieval Regression: An Age When Civilization Stepped Backward

With the fall of the Western Roman Empire, the sophisticated sanitation systems Rome had built collapsed along with it. The standard of hygiene in medieval Europe deteriorated to a shocking degree.

In medieval cities, it was common practice to dump waste directly onto the streets. In some regions, there was a custom of shouting “Gardez l’eau!” — “Watch out for the water!” — before emptying chamber pots from windows; this is said to be one possible origin of the English word “loo.”^[4] The wealthy installed a form of protruding toilet in their castles known as a garderobe — a stone structure jutting out from the castle wall that allowed waste to fall directly onto the outer walls or into the moat below. There are even records of sewage openings in castle walls being exploited as enemy entry points.

Monasteries boasted the most advanced sanitation facilities of the medieval period. Monastic toilets called reredorters used running water to flush away waste, and cleanliness standards were maintained according to monastic rules.^[4]

This deterioration in hygiene was directly linked to the spread of plague and infectious disease. The Black Death, which claimed the lives of one third of Europe’s population in the 14th century, was closely associated with these unsanitary conditions.

The Invention of the Flush Toilet: The Dawn of Modern Sanitation

Sir John Harington: The First Design, 1596

The first person to design a modern flush toilet was Sir John Harington, godson to Queen Elizabeth I of England and a courtly poet. In 1596, he described the design and mechanics of a flush toilet in detail in his work “The Metamorphosis of Ajax.”^[5]

Harington’s design placed a cistern at the top; pulling a handle opened a valve that allowed water to flow down and carry waste into the drainpipe. He actually installed these toilets at his home in Somerset and at Queen Elizabeth’s Richmond Palace. However, the lack of a proper sewage system at the time, combined with insufficient odor-blocking mechanisms, meant the invention did not spread into widespread practical use.^[5]

Alexander Cumming: The First Patent, 1775

Some 180 years after Harington’s invention, Scottish mathematician and watchmaker Alexander Cumming obtained the world’s first official patent for a flush toilet in 1775.^[5]

Cumming’s most important innovation was bending the drainpipe into an S-shape. This S-trap ensured that a certain amount of water always remained pooled in the pipe, blocking foul odors and harmful gases from the sewer from entering the room.^[5] This principle is still applied in most modern toilets today.

Thomas Crapper: Between Legend and Fact

The most famous name in the history of the flush toilet is undoubtedly Thomas Crapper (1836–1910). Because his surname became established as English slang for a toilet, the myth that he invented the flush toilet spread widely. This is, however, inaccurate.^[6]

Crapper was not the inventor of the flush toilet but rather an outstanding plumbing businessman and improver. His actual achievements are noteworthy. He opened the world’s first bathroom showroom in London in 1870, publicly promoting flush toilets to the general public at a time when they were still confined to the private quarters of the wealthy. He also held nine patents for practical improvements to the toilet, including the ballcock — a device used to regulate the water level in a cistern.^[6] The most widely accepted theory for the slang’s origin holds that American soldiers stationed in Britain during World War I saw toilets stamped with the “Crapper” brand name and began referring to toilets as “crappers” upon returning home.^[6]

The Great Stink and the Public Health Revolution: The 19th-Century Turning Point

The Industrial Revolution of the 19th century pushed the problem of urban sanitation into an unprecedented crisis. As rapid urbanization concentrated populations, major cities like London, Paris, and New York were overwhelmed by filth and disease.

John Snow and the Secret of Cholera

The cholera outbreak that struck London’s Soho district in 1854 was a world-changing event. The prevailing theory of the time held that disease was spread through bad air — “miasma.” But English physician John Snow thought differently.^[7]

Through a meticulous epidemiological investigation in which he mapped the home addresses of cholera victims, Snow discovered that the deaths were concentrated around the Broad Street pump in Soho. He persuaded local authorities to remove the pump handle, and the outbreak soon subsided.^[7] The discovery that the cause of the outbreak — which claimed 616 lives — was contaminated groundwater fundamentally transformed humanity’s understanding of waterborne infectious disease. Snow’s research is regarded as the founding event of modern epidemiology.

The Great Stink and the Construction of London’s Sewers

In the summer of 1858, the Great Stink struck London and changed the course of history. During a record heatwave, the accumulated human waste and industrial effluent in the Thames River rotted and produced an odor so severe that the curtains of the Houses of Parliament had to be soaked in lime to make them bearable.^[8] A panicked Parliament passed emergency legislation in just 18 days, and civil engineer Joseph Bazalgette was entrusted with the historic task of redesigning the entire sewer system of London.

The sewer system Bazalgette designed used 318 million bricks and 670,000 cubic meters of concrete to lay a total of 1,100 miles (approximately 1,770 km) of underground drainage channels beneath London’s streets. Completed in 1875, this system played a decisive role in sharply reducing deaths from cholera and typhoid fever by preventing contaminated wastewater from entering the drinking water supply.^[8] The foundations of modern urban sanitation engineering were established at this moment.

The Evolution of the Modern Toilet

As the 20th century arrived, flush toilets spread rapidly, particularly in developed nations. The forms we recognize today took shape: elegant porcelain toilet bowls, pressurized cistern flush systems, and the combination of separate cistern and bowl.

Japan’s High-Tech Toilet: The Washlet Revolution

At the cutting edge of modern toilet technology stands Japan. Toyo Toki (東洋陶器) — later known as TOTO — which began producing Japan’s first Western-style flush toilets in 1914, rewrote the history of the toilet in 1980 with the launch of the Washlet G Series, an electronic bidet toilet seat.^[9]

The Washlet’s core idea was to integrate the functions of a European bidet into an electronic toilet seat. An extensive ergonomic study involving 300 TOTO employees determined the optimal spray angle of 43 degrees — the so-called “golden angle.” Featuring warm water washing, a heated seat, deodorization, and even a lid that opens and closes automatically, the product spread rapidly across Japan.^[9]

As of 2016, 81% of Japanese households owned an electronic bidet, and by 2015, cumulative worldwide Washlet sales had surpassed 40 million units.^[9] The concept of the “smart toilet” became so synonymous with TOTO that the relationship mirrors that of “Hoover” and the vacuum cleaner. South Korea, similarly influenced by Japan, also ranks among the world’s highest in bidet adoption rates, where it has become an indispensable element of bathroom culture.

Toilets, Public Health, and the Global Divide

When looking back at the history of the toilet, there is a fact we must not overlook: the benefits of all this progress have not been distributed equally to every person on earth.

According to a joint report by the World Health Organization (WHO) and UNICEF, as of 2022, approximately 3.5 billion people worldwide still lack access to safely managed sanitation facilities, and around 419 million people continue to practice open defecation.^[10] The absence of safe sanitation is a primary cause of waterborne diseases such as cholera, typhoid fever, and diarrheal illness, claiming hundreds of thousands of lives every year — particularly among children under the age of five.^[10]

Recognizing this reality, the United Nations designated November 19 as World Toilet Day in 2013. The aim is to raise global awareness that access to a clean toilet is not simply a matter of convenience, but a fundamental right tied to human dignity and health.

Conclusion

The flush toilets that residents of Mohenjo-daro used daily around 2600 BCE were something 19th-century Londoners did not have. Sanitation technology has not progressed in a straight line. When the Roman Empire fell, Europe reverted for over a millennium to hurling waste out of windows — and the price was billed in the currency of the Black Death, which claimed a third of the continent’s population. The uncomfortable truth revealed by the history of the toilet is that even civilization’s most basic challenge — safely disposing of human waste — is never solved once and for all. The fact that 3.5 billion people still live without access to safe sanitation today is a reminder that this lesson remains very much unfinished.