Before the title Tenno was born, they called the position of Emperor 'Yamato Okimi' or 'Teno' domestically, and called 'Wao,' 'Wakokuo,' 'Daiwao,' and so on externally, in Wakoku (name of the country before it was called Japan).
天皇という称号が生じる以前、倭国（「日本」に定まる以前の国名）では天皇に当たる地位を、国内ではヤマト大王あるいは天王と呼び、対外的には「倭王」「倭国王」「大倭王」等と称された。