In order to commemorate the discovery of Wado (a high purity copper which does not require any refining) in the Wado, presently known as Kuroya, Chichibu City, Saitama Prefecture, the name of the era was changed to "the Wado era" and also Wado-kaichin was created.
現在の埼玉県秩父市黒谷にある和銅遺跡から、和銅（にきあかがね、純度が高く精錬を必要としない自然銅）が産出した事を記念して、「和銅」に改元するとともに、和同開珎が作られたとされる。