Once upon a time, Paul Dacre and I would meet for an annual lunch. These were pleasant enough occasions, usually in a discreet restaurant of his choosing. The conversation would generally fall into two parts: a) a shaking-of-the-head mystification at the way the world had gone downhill since, oh, about 1956; and b) an analysis of the failings of most of the other Fleet Street newspapers.

I did not personally mind the Pop Larkin nostalgia bit; and his dissection of his fellow editors’ weaknesses was invariably acute. Whatever you thought of his politics, Dacre knew what made a newspaper tick and it was always instructive to listen to his often scathing analysis of our peers.

The lunches dried up after the Leveson inquiry. Dacre was torn over the Murdoch phone-hacking revelations that led up to the hearings – at first sceptical; then briefly admiring; then furious. He was incandescent with the judge; raged at the Guardian for causing it all; and was contemptuous of our formidable reporter, Nick Davies. Davies was denounced over 3,000 words as “the man who did for the British press”. Not the man who saved Fleet Street from a moral catastrophe by holding power to account – you know, the way reporters should. No, the man who destroyed the press.

By then I’d already begun to wonder whether Dacre’s sense of reality was quite as grounded as it once had been. In mid-November 2012 the Mail had published the single most unhinged edition of a newspaper I could remember: a 12-page attack – count them! – on a man called David Bell, who was one of Leveson’s lay assessors. Bell is a former managing editor of the FT who, in retirement, sits on assorted charities, schools and trusts. He is, in the best sense of the word, a do-gooder. But his crime, in Dacre’s eyes, was to be involved with a body called the Media Standards Trust.

As chair of the Press Complaints Commission Code Committee, Dacre might have been expected to be sympathetic to such an organisation. In fact he was enraged by what he saw as a quasi-Masonic liberal elite nexus of “people who know best” – people who might conspire to inhibit the fire-and-brimstone tabloid journalism at which he excelled. This was war. If that meant deluging bewildered Mail readers with a 6,000-word tirade against someone they’d never heard of, so be it.

At least, this is my supposition of what was going on in Dacre’s head, for by now the lunches had stopped. All Dacre-watchers had to go on were the increasingly regular and virulent attacks on liberals in general, Ralph Miliband, the BBC, universities, the Guardian, human rights, the FT editor Lionel Barber, the late cabinet secretary Jeremy Heywood, immigrants, Stephen Fry, bishops, luvvies, judges, Europeans, Gary Lineker… and anyone else who had triggered some form of editorial red mist.

By now Dacre had been editing for more than 20 years and was, in the words of an anonymous executive quoted in Adrian Addison’s 2017 book, Mail Men, “the Absolute Ruler”. This executive described Dacre’s morning editorial meeting thus: “I’d watch him sitting behind this huge desk in conference, harrumphing at the news list, with all these weird courtiers trying to win points… Screeching away about ‘Alan Rubbisher’ and anything mildly liberal. Year after year, on and fucking on it went. They were utterly obsessed with the bloody Guardian, it defines exactly what they do not want their Daily Mail to be. Dacre would grumble away himself under his breath about ‘Polly fucking Toynbee’ as he marched to the lift.”

Lacking the Absolute Ruler gene, I disappeared back into civilian life more than three years ago now, and recently wrote a book about journalism, Breaking News. It contains two mentions of Dacre, and two footnotes. Yet something in it detonated another volcanic eruption. Given a platform on 4 November to reflect on his decades at the top and on where journalism is going, Dacre spent much of his Society of Editors speech laying into the liberal media in general, and my book in particular. Some of it felt a bit Steve Bannon. Most of it seemed terribly myopic and insular and – for a man with such success, riches, power and acclamation behind him – incoherently angry.

As for the paper of which he was Absolute Ruler for 26 years, it has undergone a marked change since Geordie Greig took over a couple of months ago: more reasonable, less fulminating; not so obsessive and more inclusive. It has stopped behaving like a punch-drunk old bruiser lurching around in search of a brawl. Instead, it feels like it might be ready to be part of a broader, calmer conversation about the future.

Not so long ago, an archbishop advocating that the rich should pay more tax in order to help the poor would have triggered a middling earthquake in Dacreland. The combined furies of Glover, Letts, Vine and Littlejohn would have been mobilised to pulverise the hapless prelate into tiny archiepiscopal shreds. Under Greig, the proposal provoked a civilised discussion. You can’t help thinking that, if this trend continues, Britain will feel a more congenial and open place.

If Greig can detoxify the Mail brand and prove that a tabloid can be ethical, successful and reasonably nice, what would that say about the “nasty” Dacre model? The very thought must make him very unhappy. Dacre was a big beast of a Fleet Street that no longer exists. That must also make him unhappy. Whatever his Pop Larkin nostalgia for newspapers, digital has already begun to eclipse print. He would be the first to admit he is utterly at sea in understanding the ethos or popularity of social media.

He owns 17,000 acres in the Scottish Highlands. There’s a very nice life after editing if he could only allow himself to imagine it. We might even have lunch.