Pharaoh's copper: The provenance of copper in bronze artifacts from post-imperial Egypt at the end of the second millennium BCE

The source of Egypt's copper supply during the Third Intermediate Period (1070–664 BCE) is largely unknown. Here we present new data from chemical (elemental) and lead isotope (LI) analysis of royal Egyptian artifacts of the 21st Dynasty (ca. 1010 BCE) – a period which until now was represented in the LI record only by a single artifact. Our finds identify the source of the copper in the Arabah region providing a basis for our historical reconstruction of the copper exchange network in the southern Levant at the turn of the first millennium BCE. We also analyzed two objects from the 24th and 25th Dynasties (8th c. BCE), which revealed a marked change in Egyptian copper metallurgy in both the composition (from Cu with traces of Sn to leaded copper with traces of As) and the supply chain (the Arabah ores are excluded). As the sampling involved museum artifacts, we performed X-ray imaging as a means to avoid sampling of any later metallic modifications and ensure the correct sampling process.