A law is a document of fear. More specifically, a law is a document of what a given ruling class was afraid enough of, at a given moment, to bother legislating against. When the Roman Senate passes a law in 215 BC restricting women's jewelry, the Senate is not concerned about jewelry. It is concerned about the visibility of wealth during a war effort. When Sweden bans high heels in 1710, Sweden is worried about a specific kind of foreign influence at court.
What follows are eight historical laws that sound, at first, absurd. Each one made perfect sense, in context, to the people who passed it. Each one tells you something useful about what that society was prepared to do to itself.
1. The Lex Oppia (Rome, 215 BC)
During the Second Punic War, with Hannibal advancing through Italy, the Roman tribune Gaius Oppius proposed a law restricting Roman women from owning more than a half-ounce of gold, from wearing multicolored garments, and from riding in carriages within a mile of the city except for religious purposes. The rationale was wartime austerity, though the law also served a secondary function as a way of suppressing the visible consumption habits that Rome's increasingly wealthy patrician women had developed during the preceding years of peace.
The law remained in force for twenty years. It was repealed, over the objections of Cato the Elder, in 195 BC, in a debate that Livy reports as one of Rome's first recorded political demonstrations by women, who gathered in the streets around the Forum demanding its abolition. The vote to repeal was not close. What the Lex Oppia demonstrated, and what was not lost on Cato, was that a sumptuary law could be passed but could not always be maintained against the economic trend it was trying to contain.
2. The Byzantine purple-dye monopoly (c. 4th–15th centuries)
Tyrian purple, the dye produced from the mucus of certain Mediterranean sea snails (Hexaplex trunculus and Bolinus brandaris), was one of the most expensive substances in the classical and medieval worlds. Its production was extraordinarily labor-intensive: approximately twelve thousand snails were required to produce a single ounce of dye. Byzantine imperial law restricted its use to the immediate family of the Emperor. Fabric dyed with true Tyrian purple — particularly the deepest grade, known as blatta — could not legally be sold, given, or worn by anyone outside the imperial household. Violators were subject to execution.
The law functioned. By the tenth century, purple-dyed cloth was a de facto imperial credential: anyone wearing it was, by law, either the Emperor, the Empress, or one of their immediate children. The phrase "born in the purple" (porphyrogenitus) refers literally to the Porphyra Chamber of the Great Palace, a room lined with purple porphyry, in which imperial children were born. The dye monopoly ended with the Byzantine state in 1453; the specific mollusc populations had by then been so overharvested that the industry was in decline regardless.
3. England's Window Tax (1696–1851)
William III, facing a need to raise revenue without reopening the politically toxic question of the hearth tax, proposed in 1696 a tax assessed on each house based on the number of windows it had. The logic was that the number of windows roughly correlated with the size of the house, which roughly correlated with the wealth of its occupants, and that window-counting could be done by a tax assessor from the street without entering the property (which the hearth tax had required, and which was resented).
The unintended consequence was immediate and visible. Property owners bricked up windows. The term "daylight robbery," as an idiomatic phrase for being charged too much, dates from this period; it is also a literal description of what the tax was doing to the light inside English houses. Visitors to older parts of England can still see houses with neatly bricked-up window openings, most of them dating from this period. The tax was finally repealed in 1851, after a sustained public health campaign that argued, correctly, that reducing light and ventilation in urban housing was contributing to outbreaks of typhus and other diseases.
4. Sweden's high-heel ban (1710)
King Karl XII of Sweden issued a decree in 1710 prohibiting the wearing of high-heeled shoes by women at court. The stated reason was the inappropriate foreign, particularly French, influence that high-heels were thought to represent. The underlying concern was that the Swedish court was becoming visibly over-aligned with French fashion during a period (the Great Northern War) when Sweden was militarily engaged with France's adversaries and the Swedish treasury could not afford the trade deficit that French imports represented.
The ban was sparsely enforced, but its cultural effect lasted longer than its legal life. Swedish women's court dress through the eighteenth century remained, in general, lower-heeled than French or English court dress of the same period. The law is less interesting as a fashion prohibition than as a documentary artifact of early-modern fear of soft cultural influence as a vector for political dependence.
5. France's ban on women wearing trousers (Paris, 1800)
On November 17, 1800 (specifically, the 26th of Brumaire of year IX under the revolutionary calendar), the Prefect of Police of Paris issued an ordinance requiring any woman wishing to wear trousers in public to apply to the police for written permission. The stated justification was public order: the revolutionary period had seen women adopt male dress as a political statement, and the Consulate government was trying to restore what it understood as ordinary social distinctions.
The law was almost immediately dead-letter in practice but was never formally repealed. It remained technically on the Paris legal books for 213 years. It was finally removed from the statute books by the French Ministry of Women's Rights in January 2013, which noted that the ordinance had been legally void for more than a century but had never been explicitly struck.
6. The Icelandic ban on dogs in Reykjavík (1924–1984)
In 1924, the city of Reykjavík banned dog ownership within its limits. The justification, which was medically credible at the time, was that dogs were the principal vector for the transmission of echinococcosis (a parasitic tapeworm disease) from Iceland's sheep to its human population. The ban was not repealed until 1984, after the tapeworm had been largely eradicated from Icelandic sheep through veterinary programs. Throughout the ban's sixty-year life, Reykjavík households could legally keep cats, parrots, and virtually any other pet, but not dogs.
Reykjavíkians occasionally smuggled dogs into the city anyway. There are records of dogs kept in basements and back gardens, known to neighbors, tacitly tolerated by authorities. The ban was, in its way, effective: Iceland's human echinococcosis rate dropped from endemic to negligible during the twentieth century. It was also, for the people who liked dogs, a weight.
7. The Venetian law against monopolies on gondola colors (1562)
Venice in the sixteenth century had a proliferation problem of elaborately-decorated gondolas, each family attempting to outdo the neighbors in the lavishness of its boat. The Doge's council, in 1562, issued a sumptuary decree requiring all gondolas in the city to be painted black. The logic was cost control: black paint was cheap, available, and uniform, and enforced uniformity removed the arms-race dynamic that was driving up the cost of waterborne transportation for the patrician class.
The decree is why Venetian gondolas are, to this day, black. It has never been repealed. Gondoliers who occasionally attempt other colors for tourist-targeted boats are regularly rebuked by the city authorities. A law passed in 1562 for reasons of patrician cost control has survived, functionally, as a matter of cultural branding. This happens with laws.
8. Japan's sakoku edicts (1633–1639)
Between 1633 and 1639, the Tokugawa shogunate issued a series of edicts, known collectively as the Sakoku ("closed country") decrees, that restricted nearly all travel to and from Japan. Japanese subjects were forbidden to leave the country on pain of death. Foreigners, with specific exceptions for Dutch and Chinese traders confined to the artificial island of Dejima in Nagasaki harbor, were forbidden to enter. Japanese nationals who were already abroad when the edicts took effect were not permitted to return. Christianity was banned. Foreign books in most categories were forbidden.
The edicts were enforced, with varying strictness but substantial effect, for approximately 220 years, until Commodore Matthew Perry's arrival in 1853 produced the diplomatic crisis that would lead to their formal repeal. The period of closure is one of the most sustained successful experiments in autarky in modern history. Its cultural and economic effects are still being worked out. What the Sakoku edicts show, more clearly than any other large-scale law I can think of, is that a government willing to pay the cost can substantially close a country. The cost is large. It was, in Tokugawa Japan, paid.
What laws are for
I am not, as a matter of principle, going to make a case that any of these laws were good or bad. What I think is worth noticing is that each of them represents a society's attempt to legislate against a perceived threat, and each of them had effects that substantially exceeded what the legislators were intending. The window tax produced dark houses and typhus. The trouser ban produced a dead-letter law that would embarrass the French Republic for two centuries. The Sakoku edicts produced a Japan that would, in the nineteenth century, have to re-learn how to negotiate with the outside world from a position of technological catch-up.
Laws do not only do what their authors intended. They also produce, in their enforcement and their duration, a kind of residue that shapes the subsequent society in ways the original legislators did not anticipate. The Venetian gondola is black because a Doge's council in 1562 wanted to rein in spending, and the branding consequence four centuries later was invisible to them. Which is, I think, usually what laws do.