Right from the time of the Painted Grey Ware (PGW) culture, dating to c. 1200–600 bce, more than 210 archaeological sites in India have provided evidence of glass, but there has been no attempt to date the glass‐yielding layers by radiometric techniques. This has hampered the establishment of a chronology for the beginning and evolution of glass‐making in India. The site of Kopia was excavated by the first author for three seasons from 2004 to 2006 to understand the history, development and technology of glass production in India. The excavation produced evidence of a long period of occupation, covering the Fine Grey Ware (FGW), Northern Black Polished Ware (NBP), Sunga–Kushana and Gupta periods. Twenty accelerator mass spectrometry (AMS) and radiocarbon dates, all derived from charcoal samples and processed independently by three laboratories, are available from the site. The dates range in their calibrated form on average from the ninth to the second century bce in locality I and from the second century bce to the second century ad in locality II.