From 'The Partridge - Bickerstaff Papers' (1708-1709) by Jonathan Swift

SWIFT was in London from the autumn of 1707 down to June, 1709, a period enlivened by l'affaire Bickerstaff. John Partridge, a well-known astrologer and a thorough rascal, had since the days of Charles II been putting out an annual almanac, the Merlinus Liberatus, containing predictions of forthcoming events. The wits had often attacked him but it was Swift who delivered the most telling blows. Predictions for the Year 1708, purporting to be by one Isaac Bickerstaff, also an astrologer, appeared before the end of January, 1708. Here was foretold, among other things, the death of Partridge himself, to occur on March 29 about eleven at night. March 30 saw the appearance of The Elegy on Mr. Patrige — a set of doggerel verses announcing the fulfillment of Bickerstaff's prophecy — and the prose pamphlet given here, The Accomplishment of the First of Mr. Bickerstaff's Predictions. The town, rising to the sport, contributed a number of unsigned pamphlets, one of the most amusing — sometimes attributed to Swift but not by him — being Squire Bickerstaff Detected. Swift's concluding items came out early in 1709. These were The Vindication of Isaac Bickerstaff Esq. and A Famous Prediction of Merlin.

Isaac Bickerstaff is one of Swift's happiest inventions, and it is not difficult to understand why Steele in his Tatler, launched in April, 1709, chose to prolong the career of this odd character