Standing at the center of the Quwwatul Mosque the Iron Pillar is one of Delhi’s most curious structures. Dating back to 4th century A.D., the pillar bears an inscription which states that it was erected as a flagstaff in honour of the Hindu god, Vishnu, and in the memory of the Gupta King Chandragupta II (375-413). How the pillar moved to its present location remains a mystery. The pillar also highlights ancient India’s achievements in metallurgy. The pillar is made of 98 per cent wrought iron and has stood 1,600 years without rusting or decomposing.
The pillar—over seven metres high and weighing more than six tonnes—was erected by Kumara Gupta of Gupta dynasty that ruled northern India in AD 320-540.
Some physical facts about the pillar are reasonably well-established: it is 7.3 metres tall, with one metre below the ground; the diameter is 48 centimetres at the foot, tapering to 29 cm at the top, just below the base of the wonderfully crafted capital; it weighs approximately 6.5 tonnes, and was manufactured by forged welding. But, this said, nearly everything else about the pillar is surrounded by acute controversy: For whom was it made? Exactly when? Where did it originally stand before it was moved to Delhi? What is the true import of the long inscription in Brahmi characters engraved upon it? Who placed the later inscriptions on it, and when? Who had the pillar moved to its present location, and why? What exact processes were followed in forging it into shape at that early a point of time, the 4th/5th century AD? Above all, from the scientists’ point of view, what is the secret, the great mystery, behind the fact of its being virtually non-rusting? There seems to be no end to the questions.