Sivagalai is an archaeological site and a village in the Thoothukudi district of Tamil Nadu, India, which has yielded significant evidence challenging the conventional timeline of the Iron Age. It is an Iron Age habitation-cum-urn burial site located in the Thamirabarani river valley, approximately seven kilometers north of the river. The site's significance emerged from excavations conducted by the Tamil Nadu State Department of Archaeology between 2019 and 2022, following initial discoveries by local history teacher A. Manickam.
The core finding is the antiquity of iron technology, which was previously believed to have emerged in India in the 1st millennium BCE. Radiocarbon dating of charcoal samples found alongside iron objects in burial urns at Sivagalai has been reported to date back to 3345 BCE, pushing the date of iron use in Tamil Nadu back by over a millennium. This dating, confirmed by accelerator mass spectrometry and optically stimulated luminescence testing, suggests that the Iron Age may have begun on Tamil soil around 5,300 years ago. The excavations uncovered around 160 urns and over 85 iron objects, including knives, arrowheads, chisels, and swords. Other artifacts include Tamil inscriptions dated to 685 BCE and paddy samples dated to approximately 1155 BCE.
Sivagalai is part of a rich archaeological region that connects to other major sites like Adichanallur and Korkai, which are also associated with the Iron Age in Southern India. The findings from Sivagalai, detailed in the report Antiquity of Iron: Recent radiometric dates from Tamil Nadu, have prompted a re-evaluation of global archaeological timelines, which traditionally placed the start of the Iron Age around 1200 BCE in Anatolia. The discovery has been hailed as a major breakthrough that highlights the indigenous technological brilliance of ancient India.