Radiocarbon analysis initially placed the Igbo-Ukwu material in the 9th century CE, which remains the commonly cited date. Later reassessments have discussed a broader span, sometimes from the 7th to the 13th century, showing that dating is still being refined.
The deeper roots of this skill are older still. Excavations of iron-smelting furnaces and slag at Lejja and Opi in the Nsukka region have been reported with dates as early as about 2000 BCE and 750 BCE, although the earliest dates remain debated. Either way, metalworking in Igboland has deep antiquity.