Royal Purple - Dying to be Elite in Ancient History

Who First Invented the Color Royal Purple--and How?

Hexaplex fulvescens (giant eastern murex).
Hexaplex fulvescens (giant eastern murex)., North Carolina coast. https://www.flickr.com/photos/ideonexus/2318970228

Royal Purple (also called Tyrian Purple, Phoenician Purple, Imperial Purple, Byzantine Purple and perhaps Tekhelet) is the deep purple pigment used for elite and ceremonial clothing for at least the last 2,600 years. Most famously used for clothing by the elite Romans and by Medieval monks to  illuminate religious manuscripts, royal purple was created by processing the glands of several species of the carnivorous marine mollusc called the whelk, including but not limited to Murex, Nucella and Purpura species.

Whelks which produce purple dyes are found world-wide, including the Americas (where it was also used in textile dying), but Mediterranean sea royal purple was most famously produced by the Phoenicians in or near the city of Tyre in what is today Lebanon, during the Imperial Roman period.

Science of Making Purple

The purple-bearing part of the whelk is the hypobranchial gland, which produces a colorless or yellow mucus. When exposed to sunlight and air the mucus changes color several times, but at last becomes a stable, non-water-soluble purple pigment somewhere between blue-violet and red-purple. Pliny the Elder (AD 23-79) called it the color of "clotted blood"; and it was used as a color to sanctify weddings and funerals, and to frighten the enemies of Greece and Rome.

The chemical component of shellfish purple dyes is 6,6'dibromoindigo, and that doesn't actually exist in the mollusc, but rather, as pointed out by Pliny, is generated when the gland is soaked in a vat of salt and water, reduced by boiling and exposure to a reagent, and then heated.

The specific reagent used varied throughout place and time, but honey, lead, and sunlight or combinations have been used with success.

History and Royal Purple

According to Book 8 of Pliny the Elder’s Historia naturalis, processing of whelk mucus involved adding honey or salt and water, and then placing that in a vessel made of lead and exposing it to long-term heat processing.

The legend of Melqart, reported by Herodotus, assigns the origin of the use of whelks to the god/king Heracles (known as Melqart to Tyrians), who is supposed to have used the dye to make a purple gown for the nymph Tyrus. Mycenaean pottery has been found at Knossos decorated with shellfish, and a murex shell midden on Crete has been dated to 2000 BC.

Textual references to purple dying include Nuzi in Mesopotamia (~1500 BC), the book of Exodus (~1300 BC), Ugaritic texts (1000 BC), and Akkadian texts (700 BC). Archaeological sites with evidence for whelk dying include dye workshops in the harbor at Ugarit (1500 BC) and at Troy (1400 BC). A pear-shaped jar from the reign of the Persian king Darius the Great and dated 486-485 BC contains inscriptions extolling Darius in four languages: it was painted in royal purple.

A related color known as tekhelet is mentioned in the Old Testament, and is either another word for royal purple, or a blend of indigo and 6,6'dibromoindigo, or may have been generated from cuttlefish: it's difficult to parse out the precise color and shellfish from the historical record. Tekhelet blue was used to color the blue stripes on the Jewish tallit (prayer shawl).

A 7th century AD dying workshop on the island of Inishkea North in County Mayo, Ireland, is associated with an early Christian monastery, where the monks were known to have produced whelk dyes.

Purple Prestige

The reason for the purple's "royal" status seems to come from a number of properties. First is the expense: it took roughly 250,000 shellfish to yield one ounce of the dye. In addition, royal purple was the first color-fast dye in antiquity. The Roman emperors Julius Caesar and Nero are credited with making it a color reserved for the elite, but there is clearly a deeper history.

Homer's epics use purple as an elite signal: in the Iliad, Agamemnon wore a purple cloak and Hector was buried in a golden urn swathed in purple. Odysseus and Telemachus both wear purple in the Odyssey. Cyrus the Great, king of Persia [~600-530 BC], sought purple as a royal dress, which could only be worn by non-kingly folk if it was a gift from the king.

Alexander the Great [336-323 BC] had an entire ensemble of purple clothing including a tunic, a robe, and a diadem atop a broad felt hat.

By Roman times, people wore an increasing amounts of purple depending on their status--the official friends of the Roman court were called "purpurati" or "wearers of purple"; and Caesar's court restricted "purple wearing" to all but a few select individuals on certain days of the year.

Sources

This article is a part of the About.com guide to Ancient Pigments, and the Dictionary of Archaeology.

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