Musashi Province
708 (Keiun 5):, The era name was about to be changed to mark the accession of Empress Gemmei; but the choice of Wadō as the new nengō for this new reign became a way to mark the welcome discovery of copper in the Chichibu District, Saitama|Chichibu District of what is now Saitama Prefecture. The Japanese word for copper is dō (銅); and since this was indigenous copper, the "wa" (the ancient Chinese term for Japan) could be combined with the "dō" (copper) to create a new composite term – "wadō" – meaning "Japanese copper."