Gilbert and Sullivan’s most famous work The Mikado premiered in London in 1885. It almost didn’t happen. A year earlier, Arthur Sullivan, whining about his precarious health and a 
desire to devote himself to more serious music, told W.S. Gilbert that he couldn’t bring himself to do another piece of the kind the two had previously written. Gilbert was surprised to hear of Sullivan’s qualms, having started work on a new opera in which people fell in love against their wills after taking a magic lozenge. Gilbert wrote Sullivan asking him to reconsider, but the composer replied that he was through with such operas. Gilbert, after much whining of his own, persuaded Sullivan by promising a plot in which no supernatural element occurs “. . . a consistent plot, free from anachronisms, constructed in perfect good faith and to the best of my ability.”
The Mikado was born. With a setting in Japan, an exotic locale far away from Britain, Gilbert was able to poke fun at British politics and institutions by disguising them as Japanese and, with Sullivan’s music, create one of the greatest comic operas, featuring such characters as Nanki-Poo, the wandering minstrel; Yum-Yum, Nanki-Poo’s love; Ko-Ko, the Lord High Executioner; and Pooh-Bah, the Lord High Everything Else. This is the origin of the word poo-bah — a pretty important person, a high muckety-muck, nabob, honcho, Donald Trump.
Wretched Richard's Almanac 