A Thread Through Time

Eri yarn, dyed and drying in sunlight.
© Ereena

For more than four thousand years, a silk thread lay hidden inside a string of tiny beads.

The beads came from Chanhu-daro, an Indus civilisation settlement in present-day Sindh. Within their minute perforations was a thread so fine that its story would only emerge decades after excavation, under a microscope.

It was silk.

Research by textile archaeologist Irene Good of Harvard’s Peabody Museum, Jonathan Mark Kenoyer of the University of Wisconsin–Madison and Harvard archaeologist Richard Meadow examined silk fragments from Chanhu-daro and Harappa dating to approximately 2450–2000 BCE. Published in Archaeometry in 2009, the study described the finds as the earliest evidence then known for silk outside China, roughly contemporaneous with some of the earliest Chinese evidence.

And the silk was not all the same.

Silk before the Silk Road

The familiar history of silk begins in China, with the domestication of the mulberry silkworm, Bombyx mori, and the extraordinary culture of sericulture that grew around it.

The Indus finds revealed another part of the story.

At Harappa, silk fibres survived inside copper-alloy ornaments. Microscopic analysis associated one sample with Antheraea mylitta, linked with Indian Tasar silk, and another with Antheraea assamensis, the Muga silkmoth of Assam.

At Chanhu-daro, the story became even more intriguing.

The thread preserved inside the beads consisted of dozens of silk strands, lightly twisted together. Under scanning electron microscopy, the fibres showed characteristics of silk, but their precise species could not be determined.

The researchers narrowed the possibilities to Antheraea assamensis, the Muga silkmoth, or a species of Philosamia, associated with Eri silk. In their conclusion, the researchers specifically identified Eri as one possible origin of the Chanhu-daro silk.

More than four millennia ago, the Indus civilisation was already working with several indigenous South Asian silks.

Not one silk, but many

Silk is often spoken of as though it were a single material. It isn’t.

India’s silk landscape encompasses Muga, Tasar and Eri, produced by different silkmoths and shaped by different host plants, landscapes and ways of making.

The ancient fibres suggest that this diversity was understood remarkably early. The researchers found evidence for at least two, and possibly three, species of silk being used in the Indus civilisation by the middle of the third millennium BCE.

Perhaps most fascinating is how they were being used.

At Harappa, silk survived within metal ornaments. At Chanhu-daro, it was fine enough to pass through minute beads. Long before silk became synonymous with lustrous cloth and distant trade routes, its strength and fineness were already being put to use.

Silk appears here not simply as ornament, but as material knowledge.

A clue preserved in fibre

Four thousand years leave little behind.

The researchers studied the surviving fibres microscopically, including with scanning electron microscopy, comparing their structure with known silks. The Harappa specimens revealed characteristics that allowed possible species to be identified; the Chanhu-daro thread remained more elusive.

Science has continued to sharpen the picture. In 2022, researchers developed a protein mass-spectrometry method capable of distinguishing modern Bombyx, Antheraea and Samia silks down to species level. Applied to archaeological silk from Palmyra, it identified Antheraea mylitta — Indian Tasar — providing species-level biochemical evidence for the movement of Indian wild silk in antiquity.

It raises an intriguing possibility: ancient fibres that once resisted precise identification may yet have more to tell us.

For now, the Chanhu-daro thread keeps part of its secret.

What it has already revealed is remarkable enough: South Asia’s relationship with silk stretches back more than four thousand years.

The thread continues

Today, Eri remains deeply rooted in Northeast India. The Eri silk moth, Samia ricini, originated in the region and is reared principally on castor leaves. Its character is distinct from the smooth, lustrous filament silk that the word silk usually brings to mind. Eri is traditionally spun, giving it softness, substance, warmth and a texture entirely its own.

Whether the tiny thread that passed through the beads of Chanhu-daro was Eri remains an open question. But Eri remains a vital part of India’s extraordinary silk story — and at the heart of ours.