‘Questionless the greatest subject the King had; sometime much known and beloved in all the three dominions: it was not thought safe he should live’. So wrote a distinguished contemporary of Archibald Campbell, eighth earl, first (and only) marquis of Argyll, as epitaph on one of the most significant and tempestuous careers of the British civil wars. Having embraced his earldom and the National Covenant in 1638 he remained for a decade the principal leader of the covenanting movement. He received his marquisate from Charles I, collaborated with the Cromwellians and was executed on the order of Charles II in 1661. Once characterized as ‘the dangerousest man in the state’, he was undoubtedly the major Scottish figure of an illustrious generation. He was also MacCailein Mor, chief of the Campbells, the most powerful clan in all of the Gaidhealtachd.

There has hitherto been virtually no effort to discover what political ideas, if any, influenced Argyll, probably for the good reason that, in the words of his only biographer, ‘he was one of those who rather did things worthy of being related than wrote things worthy of being read’. It is true that Argyll preferred the vita activa to the more languorous pursuits of the study, but as a committed politician he confessed a pragmatic inconsistency not generally associated (at least by scholars) with political theory or thought – ‘wise men walk not always in the same way, nor keep always the same pace, they advise according to the occurrence of affairs, and vary according to the alterations of time and interests’.