Athens used red-dyed ropes to herd citizens into the Assembly
When the Athenian Assembly was summoned, public slaves swept the Agora with ropes soaked in red ochre. Anyone dawdling there instead of heading to vote risked a stained cloak, and a marked garment could not be worn in public without advertising the fine owed for skipping. The pigment behind that trick is humanity's oldest.
Ochre is simply earth coloured by iron. Its main ingredient, limonite, gives yellow; hematite turns it red; purple ochre is chemically the same as red, its hue shifted by larger particles. Add manganese and the family darkens: sienna holds under 5 percent, umber between 5 and 20 percent.
In Africa, people were processing red ochre around 300,000 years ago, the practice peaking roughly as Homo sapiens emerged, which is why it features so heavily in debates about early human minds. At Blombos Cave in South Africa, pieces engraved with abstract designs date to about 75,000 years ago. Some Southern African groups carried deep red ochres over long distances despite having local deposits, hinting that particular shades mattered culturally. At Le Moustier in France, tool grips made from 55 percent ground ochre and 45 percent cooked bitumen, probably Neanderthal work, are Europe's earliest compound adhesive. A Welsh burial dusted in the pigment is known as the Red Lady of Paviland, and a yellow ochre horse at Lascaux is estimated at 17,300 years old.
Later civilisations gave it meaning and value. Egyptian tomb painters showed women with yellow or gold faces and men with brown, and the Ebers Papyrus of about 1550 BC describes ochre clays in medicine. The finest classical red came from the Black Sea colony at modern Sinop, sold under an official seal as sealed Sinope. Roman generals celebrating triumphs painted their faces red.
In England, travelling reddlemen sold ruddle to farmers for marking sheep. The Maori prized red kokowai; mixed with shark oil, it kept sandflies away and was believed to repel supernatural beings. The Parapara deposits drew European businesses in the 1870s, and pigment extraction there ended in 1930.
Source: Ochre
