Tennant advanced to executive chairman of Guinness in 1989. By the time he stepped down at the end of 1992, Guinness was once again internationally admired – as was Tennant himself, who at 62 was keen to take on new challenges. He became senior adviser to the London operation of the US investment bank Morgan Stanley, and in May 1993 he succeeded Lord Carrington as chairman of Christie’s – the perfect part-time job for a proven business leader with extensive social connections and the connoisseur’s eye of a private art collector.

But he had no intention of being a figurehead for the auction house, and immediately began to look for ways to improve “shareholder value”, as he had done at Guinness. His attention focused particularly on the market duopoly with Sotheby’s which meant squeezed profits for both. Accounts would later differ widely as to the precise nature of his interventions on this subject: Tennant maintained that he was completely innocent of any direct involvement in the fixing of commission structures for auction clients, or of encouraging Christie’s chief executive Christopher Davidge to collude with his Sotheby’s opposite number, Dede Brooks. But both Davidge and Brooks sought to shift blame onto their chairmen for the collusion to which Brooks confessed, and which Davidge substantiated with documents from his personal files.

What was not in doubt was that Tennant made it his business, over a series of private breakfasts in London and New York, to get to know Sotheby’s chairman and major shareholder, the real-estate tycoon Alfred Taubman. He believed firmly, from his dealings in the liquor industry, that it made sense to “size up the competition. There’s nothing wrong with that. I wanted to look him in the eye, see what sort of chap he was.” According to Tennant, however, it was “fairly barmy to suppose that two experienced businessmen could go straight into a deal on price-fixing when we had barely met”. As for the suggestion that he had instructed Davidge to break the law on both sides of the Atlantic, it was “almost laughable”.

Sir Anthony Tennant (Telegraph)