The former monk and Lloyd's of London chief, now at Salomons, was the last independent voice on the board, and his surprise departure may dent people's perception of Mr Bates.
Mr Middleton stormed out of a board meeting called this week to discuss Chelsea's future, following the untimely death of Matthew Harding - the former Lloyd's figure who brought Mr Middleton into the club.
The City was awash with rumours that Mr Middleton is now preparing a bid for Chelsea from the outside, with the backing of some chunky City investors. Mr Middleton was unavailable for comment yesterday.
Chelsea fans on dealing floors and in corporate finance parlours alike may now fear that Ruud Gullit's pipeline of cash for new players may dry up. Perhaps it is time for Chelsea fanatic David Mellor to declare Chelsea a national monument and take it over.
There was one other development yesterday, the implications of which escape me: Mr Middleton finally sold his house in North Yorkshire for pounds 160,000, several months after putting it on the market, thus severing his ties 'oop north.
Whether Mr Middleton did this because his new bride doesn't fancy life in Lastingham village near the North Yorkshire Moors, or whether he simply wants to spend more time in his house in Fulham, a convenient spot from which to plot Mr Bates's downfall, remains to be seen.
Dame Pauline Neville-Jones, the former Foreign Office high-flyer who defected to BZW when the glass ceiling in Whitehall proved impenetrable, is reaching ever dizzier heights now she's in the City.
Dame Pauline has had less than a year to get the hang of investment banking, and is already global head of business strategy for NatWest Markets.
Now she has been appointed chairman of NatWest Markets France, which opened its new Paris office last night with a client bash.
Dame Pauline says: "During my diplomatic career, I was fortunate to work closely with a number of French government representatives and had the opportunity to be a visiting fellow with the Institut Francais des Relations Internationales."
Tres bien. At this rate, I tip Dame Pauline to be the first female head of an investment bank.
The CBI conference in Harrogate promises to attract its usual hordes of top businessmen and City journalists when it kicks off this Sunday. One company which will be in the spotlight is Sea Containers, the American firm that bought the East Coast railway line when it was privatised last April.
James Sherwood, the swashbuckling chairman of Sea Containers, and his chief executive Chris Garnett, have just renamed the line the Great North Eastern Railway (GNER), and repainted the trains in snazzy scarlet and blue livery.
So will there be extra trains from Kings Cross to accommodate the CBI crowds? No. Only two trains will reach Harrogate from London in time for the civic reception on Sunday, one departing at nine and one at eleven, with both changing at York.
This conjures up delightful visions of masses of businessmen clinging desperately to the overcrowded train, in scenes reminiscent of Calcutta. But I'm sure that won't happen. This is post-privatisation rail travel, after all.
Susan Kilsby has just been appointed as a managing director in BZW's corporate finance division, where she will head the newly established consumer products sector. She joins from Bankers Trust where she had been managing director for four years, both in London and New York.
Susan's household must be a pretty hectic place - her husband Richard Kilsby has been working on new technology systems to combat insider trading at the Stock Exchange
The BBC's in-house magazine Ariel informs me that the Radio 4 programme Money Box has won the Bradford and Bingley annual award for best personal finance show on the airwaves.
Money Box has had this signal honour many times before. But it is just about the only radio programme on personal finance around, isn't it? Any other suggestions on a postcard, please.Reuse content