Question: who were the first family to be recognized as emperors of japan
Answer: 509 -- 571 AD ) , the 29th emperor , is the first for which contemporary historiography is able to assign verifiable dates ; however , the conventionally accepted names and dates of the early emperors were not to be confirmed as `` traditional '' until the reign of Emperor Kanmu ( 737 -- 806 ) , the 50th sovereign of the Yamato dynasty .