Often overshadowed by the soaring Qutub Minar , this unassuming yet enigmatic column has captured the imagination of historians, metallurgists, and curious travellers for centuries. Its enduring resistance to corrosion and the cryptic inscriptions etched upon its surface have raised myriad questions about the knowledge systems, religious traditions, and technical prowess of ancient India.
History: While the origin of the Delhi Iron Pillar remains a topic of debate and speculation, there's no definitive proof that it was brought to Delhi from another location. In the light of the description given in Pasanaha Chariu, a 1132 AD Jain Apabhramsha text composed by Vibudh Shridhar, it can be safely deduced that the pillar was already in Delhi during Anangpal's reign. The place where the Qutub Minar and the Iron Pillar are located was known as Lal Kot. Lal Kot was the name of Delhi's oldest fortified city, founded by the Tomar Rajputs. The Qutub Minar was built over the ruins of Lal Kot where scores of temples existed. The hillock of Lal Kot was known as Vishnupada (hill of the footprint of Viṣhnu), as the inscription on the pillar mentions. The Iron Pillar dates back to the Gupta period, with most scholars agreeing that it was commissioned during the reign of Chandragupta II Vikramaditya (375 AD – 415 AD), a powerful and enlightened ruler known for his patronage of art, literature, and science. Standing at approximately 7.2 metres (24 feet) in height with a 41-centimetre (16 inches) diameter and weighing over six tonnes, the pillar was likely part of a temple dedicated to Lord Vishnu.
Metallurgical Marvel: Perhaps the most astonishing feature of the Iron Pillar is its incredible resistance to corrosion. Forged over 1,600 years ago, it has withstood monsoons, heat, humidity, and human contact with minimal rusting. This has led many to speculate whether ancient Indian metallurgists had access to alchemical secrets lost to time. Such metallurgical ingenuity testifies to the advanced scientific knowledge prevalent in Gupta-era India. At a time when iron rusted away within decades in other parts of the world, Indian blacksmiths were forging masterpieces that would last millennia.
Modern metallurgical studies suggest that the iron used in the pillar is of exceptionally high purity, with a surprisingly low content of sulphur and manganese. The Iron Pillar of Delhi resists corrosion due to a unique passive film formed on its surface. Forged through ancient Indian smithing without lime, the iron is rich in phosphorus—unlike modern steel—which reacts with environmental moisture to create a slow-forming, protective phosphate layer. This layer, chiefly comprising misawite and crystalline iron hydrogen phosphate hydrate, seals the metal-rust interface, impeding rust. The slag and unreduced oxides in the iron aid passivation by altering corrosion dynamics. Alternate wetting and drying cycles further foster this natural defence. Over these many years, this film has grown merely one-twentieth of a millimetre thick. This layer is believed to have been the result of deliberate craftsmanship combined with Delhi’s semi-arid climate.
Inscriptions: Carved in the Brahmi script, the Sanskrit inscription on the Iron Pillar is a poetic eulogy, lauding a mighty king who defeated enemies in battle and whose fame reached beyond the seven seas. Most historians identify this ruler as Chandragupta II. The inscription not only confirms the pillar’s religious and political associations but also provides rare evidence of the linguistic and literary sophistication of the era. The verse is written in chaste Sanskrit, displaying a command of poetic metre and a reverence for dharma. Interestingly, the script also provides important clues for deciphering the evolution of Indian epigraphy and calligraphy over the centuries.
Significance: Beyond its metallurgical wonders and historical inscriptions, the Iron Pillar has held a place of reverence in the cultural imagination. Dedicated to Lord Vishnu, the pillar once supported a Garuda capital—an emblem associated with the deity. This reinforces the notion that the structure had a strong religious function, possibly serving as a dhvaja-stambha (flagstaff) in a temple complex. In later centuries, it became the subject of local legends. A popular belief held that if one could encircle the pillar with their arms while standing with their back to it, their wishes would be fulfilled. Though such practices have now been prohibited to protect the pillar, they speak volumes about its place in folk memory.
It stands today not just as a relic of the past but as a living conversation between civilisations—between kings and craftsmen, faith and form, science and sanctity. To visit the Iron Pillar is to be reminded of a time when the synthesis of art, metallurgy, and devotion produced wonders that continue to baffle and inspire in equal measure.