Recent excavations in Uttar Pradesh have turned up hundreds of iron artifacts, furnaces, tuyeres and slag in radiocarbon layers dated between c. BC 1800 and 1000. This raises the question of whether iron working was brought to India during supposed migrations in the second millennium BC, or was developed indigenously and independently by adopting traditional methods. More than 100 sites have been explored in Uttar Pradesh. In the past, archaeometallurgists have conducted chemical analysis and metallographic examination of iron artifacts from various sites to learn how the Iron Age developed in Uttar Pradesh. Evidence of local smelting is suggested by the occurrence of slag at Hastinapur, slags and crucible fragments at Hulaskhera, and slags and unfinished tools at Khairadih. A very important site is Attranjikhera where slags and ores have been discovered. Chemical and metallographic analyses have been done on early historic iron artifacts at Rajghat. These comprised nails, blades, arrowheads, a rod and an unidentified object. Studies have also been reported on some artifacts from Kausambi that were found to have a steel structure. Examinations were conducted in our laboratory on artifacts from Attranjikhera, Allahapur, Sooron, Jajmau, Hulaskhera, Bhardwaj Ashram, Sringverpura and Khairadih. Studies have indicated that iron technology was in a preliminary stage at Attranjikhera and Allahapur during 1000 BC and 400–300 BC respectively, but that it developed more fully around 600 BC– 500 AD. Jajmau smiths were quite advanced even in 600 BC and had good knowledge of lamination and heat treatment. At Hulaskhera, iron technology developed from 400 BC–500 AD and knowledge of lamination and heat treatment was acquired in 200 BC. Iron artifacts from Kausambi, Sringverpura and Bhardwaj Ashram – sites near Allahabad – revealed that iron technology was quite advanced from 800 BC on as they were able to produce lowcarbon, mild and medium-carbon steel from wrought iron. The Iron Age in Uttar Pradesh began around 1800 BC and technological advances such as lamination and heat treatment were made later on, around 600–200 BC.