A hundred years ago, on September 20, 1924, the world learned about the Indus (Harappan) civilisation for the first time when John Marshall, then director general of the Archaeological Society of India, wrote about it in The Illustrated London News. It was based on two similar seals found first in Harappa and then in Mohenjo-daro, cities separated by over 500 km. The dating was actually done through a ‘Letter to the Editor’ by Professor A.H. Sayce on September 27, 1924. He recognised the seals as identical to those he had found in Sumer, dated to 2300 BC.
Originally described as Indus-Sumerian, it was soon clear that this civilisation had developed independently, and so was renamed Indus. But with sites found beyond Indus, in the mountains of Afghanistan in the west, the dry river bed of the Ghaggar-Hakra in the east, and the coast of Gujarat in the south, the civilisation is now named after the first city discovered — Harappa.
Now, we know that these cities played a key role in the supply of the much-in-demand lapis lazuli — the deep blue semiprecious stone used in sacred ornaments — and tin, which was needed to make the alloy bronze. Both raw materials were obtained from Central Asia and from present-day Afghanistan. It........