As I took a break not long ago from putting the first draft of my dissertation on an Amstrad, I turned on BBC Television and saw my country cruising for a bruising in the Gulf. And yet on the same day I received a letter from America solemnly informing me of a spectacular line-up of planets in the astrological sign of Leo which was to herald a new era of world peace. The writer added that the day also marked the end of the Mayan calendar – how the remnant Mayans are now expected to date their letters she did not volunteer. The reason, I conjecture, why a sober-minded academic should be moved to alert me to these revolutions has to do with her knowledge that for the past four years my scholarly interests have centred on the political prognostications of the English Civil War’s astrologers. It could be worse. Another American academic once responded to the dissertation topic by remarking that he had recently had his ‘biorhythms’ done. Herbert Butterfield, whose notion of Whiggishness continues to provoke among English historians even more examinations of conscience than St Benedict recommended, warned against historians like me. Those who specialise in fields such as alchemy ‘seem to become tinctured with the kind of lunacy they set out to describe’. With this in mind, I scan my psyche periodically for evidence of taint. Here colleagues are of little use, since my choice of topic long ago rendered them incapable of discerning the fine shades indicative of the onset of celestial lunacy.