One afternoon in mid-July 2000, I got a call from Alex Salmond, whose biography I was then working on. An hour or so earlier, to the surprise of pundits and political friends and foes, he had stepped down as leader of the Scottish National Party. He invited me to his office at the Scottish Parliament at Holyrood in Edinburgh, where I found him de-mob happy. What, he was eager to know, were people saying about his resignation?

There were three rumours doing the rounds. The first was that either he or his wife, Moira, seventeen years his senior, was terminally ill. The second was that he was in debt to an Irish bookmaker, who was threatening to expose his gambling habit if he did not cough up. I kept the juiciest to last: it was said that he was having an affair with his young protégée, Nicola Sturgeon, whom he had appointed to his shadow cabinet the year before.

Salmond’s reaction to this was one of amusement. Over the years, he had grown inured to the media’s attempts to smear him in the hope that it would ultimately suffocate the idea of Scotland’s separation from the United Kingdom. No newspaper, for example, supported the cause and the SNP