Photo: Hridya08 · CC BY-SA 4.0
Science · c. 400 CE

Iron pillar of Delhi

Found
Standing in the Qutb complex at Mehrauli, Delhi, inside the court of the Quwwat-ul-Islam mosque
Kept at
In place; fenced since 1997

A 7.2-metre wrought-iron column of about six tonnes, forged as a dhvaja of Vishnu and still almost free of rust after sixteen centuries.

What it says

The Sanskrit verses say a king named Chandra, who defeated the Vangas and crossed the seven mouths of the Sindhu to conquer the Vahlikas, set up this lofty standard of Vishnu on the hill called Vishnupada. Most scholars identify Chandra with Chandragupta II. A later short inscription names Anangapala, the Tomara king.

What it proves

Metallurgists, among them R. Balasubramaniam of IIT Kanpur, showed its high phosphorus iron forms a thin protective film, proof of forging skill on a scale Europe did not reach for many centuries.

Evidence for