In one sense, the origin of these lectures goes back to the day, about thirty years ago, when, in the (then) dusty back room of Wildy's shop in Lincoln's Inn Archway, I picked up a copy of Robertson's two-volume report of the Court of Session proceedings in the first Auchterarder case. Some years later, I bought a copy of Orr's report of the Free Church case in the House of Lords. But I would never have got round to writing anything based on these finds without the invitation of the Trustees of the Jean Clark Foundation to deliver the inaugural series of lectures in memory of the late Jean Clark in May 2007. In retrospect at least, I am grateful to them for that stimulus.

The text of the lectures has been substantially revised for publication. In particular, I have added footnotes and expanded the first lecture to cover the Stewarton case, which I had to omit from the oral version for reasons of time. Nevertheless, the lectures remain simply lectures: they do not pretend to be the much-needed modern authoritative account of the crisis.

The theme is a constitutional crisis, not only for the Church of Scotland, but also for the courts, and indeed for the country as a whole. What makes the cases which I discuss unusual, if not unique, is the vast amount of available material about them in special law reports, newspapers, pamphlets, books and memoirs.