 The Imperial House recognizes 126 monarchs beginning with the legendary Emperor Jimmu (traditionally dated to 11 February 660 BC) and continuing up to the current emperor, Naruhito; see its family tree.Historical evidence for the first 29 Emperors is marginal by modern standards, but there is firm evidence for the hereditary line since Emperor Kinmei ascended the throne 1,500 years ago.of the defines as the ; the ; the ; the , and ; the ; the and ; and the .