Although he was formally a retainer appointed by imperial edict, he was in fact the ruler of Japan who even held sway over the Imperial Court, and typically was treated as the king by outsiders.
形式的には勅令により任命される臣下ではあるが、実質的に朝廷をも押さえた日本の統治者であり、対外的にも国王としての待遇を受けるのが通例であった。