If you have distant ancestors from Central Asia, the Middle East, North Africa, and Europe, they would likely approve of our love of blues. Blues are so ubiquitous today in the West that in some cases they almost become a neutral. Blue jeans, blue socks, blue shirts, blue suits. Blue blankets, blue towels, blue kitchen rugs, blue painted houses. References to blue dye has even worked its way into the English language with idioms such as blue collar, true blue, and singing the blues. Those same ancestors might be surprised, however, to discover that we are no longer using woad to dye those blues.

Woad, Isatis tinctoria, is a rather unassuming plant from the Brassicaceae, or mustard family. Growing in a leafy rosette from a taproot, it typically only blooms in its second year, sending up tall stalks with yellow blossoms. That deep taproot lets woad pull moisture from deep below the surface during dry weather, making it well adapted to the mountains, steppes, and semi-arid regions of Central and southwestern Asia. The earliest archaeological evidence of woad may date to around 34,000 years ago in Dzudzuana Cave in Georgia. Spectroscopic analysis suggests that plant material, possibly woad, was processed on stone tools, although it is unclear whether it was used for creating dye or medicine. It is possible that woad might have been used for both purposes; it was used for millennia to treat wounds, helping to stop bleeding and prevent infection.

Although archaeological evidence points to thousands of years of woad use across Central Asia and the Middle East, early written references to woad are a bit scarce. Some modern Akkadian scholars argue that the word for woad appears on tablets dated to around 2200 BCE, though other scholars say it may just as easily refer to lapis lazuli. After that, the next written record of woad does not appear until around 200 CE, when woad appears in the Mishnah. In it, priests (kohen) are instructed not to perform blessings if their hands are stained with woad, as the color could distract the congregation. Notably, while blue textiles appear in earlier trade records, woad itself does not, at least not in sources discovered so far.

Woad spread from Central and southwestern Asia through the Middle East, over to North Africa, and into Europe. It had reached the Levant and Sinai by at least the 10th century BCE, with woad-dyed textiles recovered from Iron Age sites. Given the proximity, it is reasonable to assume it was also present in North Africa, though the earliest archaeological evidence comes from woad-dyed linen mummy wrappings in Egypt dated to around 2500 BCE.

Woad likely arrived in Europe along Mediterranean migration routes during the early to mid-Neolithic before heading north into the rest of Europe. Carbonized woad seeds found in the cave of l’Audoste in southern France, dated to 5000–4500 BCE, suggest a fairly early presence, though their intended use is unknown. By around 1500 BCE, pieces of woad-dyed textiles were left in the salt mines of Hallstatt, Austria. By the late Iron Age, woad had made its way to the British Isles and Scandinavia. Seeds, pods, and dyed textiles from around the 1st century BCE have been found in places like North Lincolnshire, England and Skærsø in Denmark, preserved by waterlogging and anaerobic conditions.

For centuries, woad was grown and used locally across Central Asia, the Middle East, North Africa, and Europe. However, trade seems to have focused more on finished textiles than on the plant itself. By the Middle Ages in Europe, woad was ready to break out as a trade good in its own right. A surge in the popularity of blue swept through Europe in the 1100s. Historians still discuss why this might have been, but one particularly persistent explanation is the growing depiction of the Virgin Mary in blue by the Catholic Church, which helped elevate the color’s status. This popularity led to an increase in blue in heraldry and it was adopted as a royal color in France under King Philip Augustus. France and Germany began to build extensive woad industries, from cultivation to processing to trade, while England and Italy developed smaller, but still impressive, production.

Very quickly, woad became immensely profitable. Blue surged in demand, and previously fashionable reds from madder lost ground. But that shift did not happen quietly. Conflicts broke out between woad and madder merchants and guilds, sometimes escalating into outright fights. There were also some more, shall we say, creative efforts at persuasion. Madder sellers commissioned and donated stained glass windows for churches and cathedrals depicting blue devils and blue hellfire in attempts to literally demonize the color.

If you have distant ancestors from Central Asia, the Middle East, North Africa, and Europe, they would likely approve of our love of blues. Blues are so ubiquitous today in the West that in some cases they almost become a neutral. Blue jeans, blue socks, blue shirts, blue suits. Blue blankets, blue towels, blue kitchen rugs, blue painted houses. References to blue dye has even worked its way into the English language with idioms such as blue collar, true blue, and singing the blues. Those same ancestors might be surprised, however, to discover that we are no longer using woad to dye those blues.

Woad, Isatis tinctoria, is a rather unassuming plant from the Brassicaceae, or mustard family. Growing in a leafy rosette from a taproot, it typically only blooms in its second year, sending up tall stalks with yellow blossoms. That deep taproot lets woad pull moisture from deep below the surface during dry weather, making it well adapted to the mountains, steppes, and semi-arid regions of Central and southwestern Asia. The earliest archaeological evidence of woad may date to around 34,000 years ago in Dzudzuana Cave in Georgia. Spectroscopic analysis suggests that plant material, possibly woad, was processed on stone tools, although it is unclear whether it was used for creating dye or medicine. It is possible that woad might have been used for both purposes; it was used for millennia to treat wounds, helping to stop bleeding and prevent infection.

Although archaeological evidence points to thousands of years of woad use across Central Asia and the Middle East, early written references to woad are a bit scarce. Some modern Akkadian scholars argue that the word for woad appears on tablets dated to around 2200 BCE, though other scholars say it may just as easily refer to lapis lazuli. After that, the next written record of woad does not appear until around 200 CE, when woad appears in the Mishnah. In it, priests (kohen) are instructed not to perform blessings if their hands are stained with woad, as the color could distract the congregation. Notably, while blue textiles appear in earlier trade records, woad itself does not, at least not in sources discovered so far.

Woad spread from Central and southwestern Asia through the Middle East, over to North Africa, and into Europe. It had reached the Levant and Sinai by at least the 10th century BCE, with woad-dyed textiles recovered from Iron Age sites. Given the proximity, it is reasonable to assume it was also present in North Africa, though the earliest archaeological evidence comes from woad-dyed linen mummy wrappings in Egypt dated to around 2500 BCE.

Woad likely arrived in Europe along Mediterranean migration routes during the early to mid-Neolithic before heading north into the rest of Europe. Carbonized woad seeds found in the cave of l’Audoste in southern France, dated to 5000–4500 BCE, suggest a fairly early presence, though their intended use is unknown. By around 1500 BCE, pieces of woad-dyed textiles were left in the salt mines of Hallstatt, Austria. By the late Iron Age, woad had made its way to the British Isles and Scandinavia. Seeds, pods, and dyed textiles from around the 1st century BCE have been found in places like North Lincolnshire, England and Skærsø in Denmark, preserved by waterlogging and anaerobic conditions.

For centuries, woad was grown and used locally across Central Asia, the Middle East, North Africa, and Europe. However, trade seems to have focused more on finished textiles than on the plant itself. By the Middle Ages in Europe, woad was ready to break out as a trade good in its own right. A surge in the popularity of blue swept through Europe in the 1100s. Historians still discuss why this might have been, but one particularly persistent explanation is the growing depiction of the Virgin Mary in blue by the Catholic Church, which helped elevate the color’s status. This popularity led to an increase in blue in heraldry and it was adopted as a royal color in France under King Philip Augustus. France and Germany began to build extensive woad industries, from cultivation to processing to trade, while England and Italy developed smaller, but still impressive, production.

Very quickly, woad became immensely profitable. Blue surged in demand, and previously fashionable reds from madder lost ground. But that shift did not happen quietly. Conflicts broke out between woad and madder merchants and guilds, sometimes escalating into outright fights. There were also some more, shall we say, creative efforts at persuasion. Madder sellers commissioned and donated stained glass windows for churches and cathedrals depicting blue devils and blue hellfire in attempts to literally demonize the color.

The blue dye created from what we know as the true indigo plant, Indigofera tinctoria, was known in Europe during the Middle Ages, but was often prohibitively expensive since it came all the way from India and other parts of Asia. Despite their different origins, both indigo and woad can produce the same blue coloring compound, indigotin, although true indigo yields more of it than woad. Additionally, most dyers during the early Middle Ages believed that dye from true indigo was a type of mineral, with some merchants even referring to it as “India stone.” This perception was likely because the indigo arrived already processed in blue powder and pressed into blocks that resembled soft stones. Woad, however, was traded in balls of dried, pulverized leaves. It would take a few centuries, but by the 1600s most dyers understood that these indigo blocks arriving with traders from the east were produced from a different dye plant and not mined from the earth. Around the same time, the fortunes of those in the woad industry were about to change.

As Great Britain’s East India Company established trade routes during the 1600s, the cost of blue dye produced from true indigo began to drop precipitously. It quickly became clear that it was cheaper to import indigo dye from India than it was to manufacture blue dye from woad. Woad growers, merchants, and dyers panicked as their previously profitable industry faced risk of collapse. Protectionism set in. Woad merchants in Germany began to refer to indigo as the Devil’s Dye and claimed that it was “an injurious, deceptive, corrosive, and diabolical article.” Woad growers, dyers and merchants in England saw the threat as early as the late 1500s with indigo being branded as poisonous, a drug, and “food for the devil.” Accordingly, indigo was forbidden in England from 1581 to 1660. In 1598, France declared that importers of indigo would be put to death and continued to publish additional edicts to that effect in 1609, 1624, and 1642. The Holy Roman Emperor banned it in 1607, with execution to be dealt out to any merchants selling it or dyers using it. The Electorate of Saxony banned it as well in 1650. In Nuremberg, dyers were told they faced execution if they did not annually renew their oath to not use indigo.

Attempts to suppress the importation and use of indigo would ultimately fail. Despite threats of death or other less lethal reprisals, indigo still managed to turn up the places it was banned. By 1737, prohibitions against indigo had disappeared and woad’s decline followed. Although woad did not entirely disappear from Europe, it was increasingly used only as an assist in the fermentation of indigo vats.

Woad did see one final, but brief, resurgence. In 1806 Napolean created a blockade to cut off the British Empire from its trade with Europe. However, this also cut off France’s supply of indigo dye from the East India Company, which had near exclusive access to Indian indigo. Without blue dye, French military uniforms could not be produced in their traditional color. For a year, a number of Napolean’s regiments had to wear white uniforms. Napolean responded to this challenge by declaring a contest to find a useable blue dye for uniforms, and woad production soared back into popularity. By June 1807 French uniforms were once again blue, this time dyed with woad. However, woad’s revival would be short lived. Once indigo became available again, woad was quickly abandoned.

Woad steadily declined over the next couple of centuries. Although it spread throughout the world wherever European colonists settled as either a primary or secondary source of blue dye, woad would eventually become not much more than a weed. By 1932, the last commercial woad harvest in England took place in Lincolnshire, England. And although indigo remains a popular natural dye, it has also seen a decline in demand over the last 125 years due to the invention of synthetic indigo in 1897. Today, synthetic indigo dominates the market, with over half of its annual production being used in denim alone.

Woad is still sometimes used for dye today, though not as it once was. It is grown in small quantities by hobbyists interested in traditional dyeing, or gathered from the roadside and fields where it is often considered to just be another weed. In Europe, projects such as the Spindigo initiative from the early 2000s explored whether woad might return as a viable natural dye crop, though with limited success. In North America, it has taken on a very different role. In many states west of the Rocky Mountains, it is classified as a noxious weed, as it spreads aggressively.

Woad spent thousands of years as one of the most reliable ways to produce blue across a good swath of the world. It shaped cultures and held its place through long stretches of change. Its decline ultimately says less about the usefulness of woad itself than about the rapidly changing world in which it existed, and still exists. Woad now remains as a quieter presence. Whether in a dye pot or along a roadside, it still points back to a much longer history of how people made color before global trade and industrial chemistry rewrote how we interact with textiles and dyes.