“My true name is so well known in the records or registers at Newgate, and in the Old Bailey, and there are some things of such consequence still depending there, relating to my particular conduct, that it is not be expected I should set my name or the account of my family to this work; perhaps, after my death, it may be better known; at present it would not be proper, no not though a general pardon should be issued, even without exceptions and reserve of persons or crimes.” - Moll Flanders
It’s got to be the longest first line.
I don’t know what the longest first line ever published is; but my 38 beats your Moll Flanders by many words and many more characters :-)