It says that the character 王 (king) is a hieroglyphic character representing a war ax and the figure with a bib symbolizes a blacksmith and, therefore, it was a powerful clan that was among the first to introduce the use of iron forging.
王の文字はマサカリの象形文字で、腹掛け姿は鍛冶を象徴することから、いち早く鉄文化を手に入れた豪族というものである。