Mikado (Japanese Mi for exalted, and Kado for gate), is an ancient and poetic title of the Japanese emperor, similar to the Sublime Porte title of the Ottomans; probably transferred to the ruler and judge from the gateway to his palace, where he did justice.
It was never a separate title for a spiritual ruler; this incorrect idea results from the historical fact that much of the mikado's or emperor's temporal power was usurped before 1867 by shoguns or generals, who, however, always admitted that they derived their power from him.
The present mikado, Emperor Akihito (reign January 1989 to present) is the 125th of his line, which legend dates back to 660 B.C.; of him the title mikado, essentially a foreign solecism, is much less used than Dai Nippon Tcikoku Tenno, "Imperial Son of Heaven of Great Japan."
Tenno corresponds to the English word emperor.