“Warning — this report contains flash photography” was how every news bulletin began tonight, as the engagement of Prince William and Kate — now Katherine — Middleton was announced. That was something of an understatement.

As the happy couple stood before a deep red portrait wall in St James’s Palace, she in a deep blue dress, he balding and already looking a little aardmanish, they were engulfed in a blizzard of light flashes, as if a meteor shower was happening off-camera.

Having known each other for eight years, after meeting at the University of St Andrews, and with a break in between, the couple became engaged four weeks ago during a trip to Kenya.

As William told assembled reporters — your correspondent watched it at home, while making a baked bean bap — he proposed to Kate with Diana’s engagement ring, a huge square sapphire in a diamond setting which Kate promptly displayed. The damn thing looked like something out of a Dynasty episode, a sudden blast of the ’80s.

“She couldn’t be here, obviously,” Prince William said, “so this is one way in which she is.” It was not at all creepy, I can assure you of that. Having your dead mother’s ring on your girlfriend’s hand. No one was thinking that at all.

Yes, dear reader, I am gagging too, but it’s news so let’s push on.

The photo call was late afternoon. I admit I barely noticed the news at all, reading Marxist analyses of the eurozone crisis. Won’t be too big a thing, I thought.

How wrong I was.

I went out to the Dodo corner shop, and they were even talking about it in jaded Soho.

“Have you seen it?” said the hefty Pakistani behind the counter, whose conversational repertoire is usually confined to “we don’t have that” and “madam I will call the police”. “She is the first commoner to marry a royal for 400 years.”

Gaaaaak. True enough. The Middletons are former flight staff who made a mozza out of mail-order party supplies. Doesn’t get more commoner than that. There was a time a girl from that sort of family who got near the heir to the throne would have been tasered. I bet Prince Philip hasn’t even been told yet.

Anyway, this was just the beginning. By 6pm the whole TV schedule had been rearranged for coverage of the damn thing. Top of the list was an exclusive ITV interview with Tom Bradby, a friend of William’s who had helped to finger Clive Goodwin, the Murdoch scribe who was ultimately jailed for illegal phone tapping, with hopefully many more to follow. Of the interview, here’s a sample:

Tom: Kate, you’re going to be the envy of many?

KM: Well, I just hope I look after it. It’s very, very special.

Tom: It has to be said, you both look incredibly happy and relaxed.

William: We are. We’re like sort of ducks, very calm on the surface with little feet going under the water.

And so on for 20 minutes.

Radio Girl came in at this point, back from Slough: “Everyone’s talking about it on the train … it’s the only time I’ve seen the British talk to strangers.”

On the TV, Prince Charles was interviewed: “Are you happy about the engagement, Sir?” “Very, they’ve been practising long enough.” Che? Ah well, not every day your only son gets engaged.

Switch channels and the line was being tamped down: “The wedding that will cheer up austerity Britain.”

Bizarre as it was, people were beginning to say this. Sensible people. People you thought you knew well.

Back to the news: apparently, the cabinet greeted the news of Prince William and Kate Middleton’s marriage with a “great banging of the table”. Cut to the PM from No. 10:

“This is incredibly exciting news and I’m sure the whole country will want to pass their very best wishes to the happy couple …”

So I say again, gaaaaack.

Newsnight, the BBC’s flagship show, went with a panel of experts — two historians, Simon Schama and David Starkey, Boris Johnston’s sister who edits The Lady and Martin Bashir in New York. They tried to talk about the history and how this was the next vital step in fusing the royal family with common Britain, and so on and so forth. Then they couldn’t hold it any longer and talked about which church it should be held in like a bunch of tweens at a Jonas Brothers suds party.

Then the engagement shots again, and Diana’s ring on her finger. Am I the only one wondering if it’s on her jack-off hand?

Finally, some BBC package that had been prepared months before, featuring Piers Morgan — “this is a large dose of royal Viagra” — an old ra ra friend Julian — who’s a “member of classical boy band Blake” — and a bottle blonde would-be reality star passing herself off as a personal friend — “yeah they rent videos and microwave stuff together”.

The wedding is likely to be in June next year. We wish the couple every happiness and a life sufficiently long to end it as private citizens in the Republic of England.