Hanky-panky

[Aquagility]

When was hanky-panky first used? C.S.Forester assumes it to have been around in early C19 (The Happy Return).

[Quizmonster]

Punch magazine 1841, but then it just meant trickery.

[Aquagility]

Thanks, QM, I knew I could rely on you. Forester was out by some 35 years, then.

[jno]

Punch would be just the first written use that has come down to us, of course. Most words are formulated well before they're written down. Cassells' slang dictionary suggests it comes from either Romany or from the hanky used by conjurors in doiwng tricks. So Forester could have been making a sensible guess.

[Quizmonster]

Obviously, J, the first written - or, nowadays, otherwise recorded - instance of a word or phrase's usage has to be taken as its earliest use. I'm sure we all know perfectly well that it was probably around in speech prior to that.
Perhaps, in the early 1800s, a fisherman in Kent looked anxiously across the Channel to where Napoleon was gathering an invasion force and said, "We will fight them on the beaches...we will never surrender!" and so on. However, as neither he nor anyone else wrote the words down, we're forced to conclude that Churchill originated the phraseology.

[heathfield]

Loved Lionel Jeffries line in one of his films... 'So much for the hanky... Now for the panky!'