The 1600 year old Delhi iron pillar has attracted the attention of archaeologists, metallurgists and corrosion scientists for its excellent resistance to corrosion. The book details new insights on the Delhi iron pillar based on the researches of the author. The identities of the patron Chandra and the original location Vishnupadagiri of the pillar have been critically analyzed. The engineering details of the pillar, including its decorative bell capital, have been highlighted, and the manufacturing method of the pillar has been elucidated. The important aspect of corrosion resistance of the pillar has been discussed in light of a detailed characterization of the pillar's protective passive surface film. Several metallurgical aspects concerning ancient Indian iron have been presented. The book concludes with a discussion of other large forge welded ancient iron objects in India.