The first Emperor to become Daijo Tenno was Emperor Jito, who handed over the throne to Emperor Monmu, (though there is an example of Empress Kogyoku, who transferred the throne to her younger brother Emperor Kotoku, but at this time, there was no title of 'Daijo Tenno' and, thereafter, she acceded to the throne again as Empress Saimei) and up until Emperor Kokaku handed over the throne to Emperor Ninko in the late Edo period, there were 62 Joko's in total.
持統天皇が文武天皇に譲位をして太上天皇になったのが最初であり（皇極天皇が弟・孝徳天皇に譲位した例はあるが、このときには「太上天皇」号は存在しておらず、また、その後斉明天皇として重祚している）、江戸時代後期光格天皇が仁孝天皇に譲位するまで、計62人の上皇が存在した。