Keikō

Emperor Keikō , also known as Ootarashihikooshirowake no Sumeramikoto (大足彦忍代別天皇) was the 12th legendary Emperor of Japan, according to the traditional order of succession. Both the Kojiki, and the Nihon Shoki record events that took place during Keikō's alleged lifetime. Keikō was recorded as being an exceptionally tall emperor who had a very large family. During his reign he sought to expand territorial control through conquest of local tribes. He had a very important son named "Prince Ōsu", who was in possession of the Kusanagi when he died. This treasure was later moved to Atsuta Shrine, and is now a part of the Imperial Regalia of Japan. There is a possibility that Keikō actually lived or reigned in the 4th century AD rather than the 1st, but more information is needed to confirm this view.