The UK Supreme Court yesterday ruled that 27 'black spider' memos sent to the government by Prince Charles in 2004-5 may be published. Judges overruled a bid by Dominic Grieve, the former attorney general, to gag publication. Thoughts that Charles has previously shared only with his mother's ministers and sympathetic root vegetables may now see the light of day. In response to the Supreme Court decision, the prime minister shared his 'disappointment' with a grieving nation, while the prince's office said that 'Clarence House is disappointed that the principle of privacy has not been upheld.’

No doubt a public figure is entitled to privacy, even one whose inner life has metonymied into the clay of 'Clarence House'; it seems mansions have feelings, too. But the concept of royal privacy has a sticky history. It can be argued that the origins of modern governance lie in Henry VIII's lavatory arrangements, where the Groom of the King’s Close Stool – a flunkey on hand to deploy a sponge, ramrod-fashion, at the critical moment – occupied a key role in Privy Chamber administration. Here 'privy', as in the still-extant Privy Council, does duty for 'secret' as well as 'private', and there lies the rub. For most people, private and public stand distinct. From a royal's eye view, though, as affairs of state are personal, privacy is a more a matter of official secrecy. This is how the dauphin can have have his Duchy Original organic English white muffin and eat it. His jottings jump the queue of green-ink nutter letters to ministers, but when charged with wielding influence, the privacy card remains on hand.

David Neuberger, for the Supreme Court, observed that publication couldn't be stifled 'simply because, on the same facts' the attorney general happened to take 'a different view from that adopted by a court of record’ – the tribunal set up under the Freedom of Information Act 2000 – ‘after a full public oral hearing', even if Grieve's view was reasonable. Neuberger's judgment, endorsed 5-2 by the court, in effect says that a private opinion, even that of a government official, has no more than private standing when set against that of a legally competent authority such as the FoI tribunal.

Neuberger's views on public accountability aren't universally shared. It isn’t only the prince who clings to a Tudor vision of government. Another Henrician innovation was to bring in the 'omnicompetence' of parliamentary statute as a tool of the royal will. According to Wednesday's Sun, Cameron had promised Charles legislation to ban the letters' release. After the verdict, the prime minister voiced the 'principle' that senior royals should be 'able to express their views to government confidentially. I think most people would agree this is fair enough' – fair enough, that is, if you think a private family should be able to lean on politicians to modify democratic decisions. It's a strange claim for a politician to make in the run-up to an election.

After the verdict, the former MP, convicted fraudster and demoted Privy Councillor Denis MacShane, who had access in government to some of Charles's letters, suggested on Twitter that publication may prove disappointing. No doubt the memos advance Charles's vision of tweed and free-range yokels. Yesterday's decision, apart from cutting back secrecy, may serve a useful proleptic purpose, in making him less likely to bend ministers' ears, though he can take comfort from King Carl XVI Gustaf, who recently summoned Sweden's foreign minister, Margot Wallström, to the palace after she criticised the repression of women in Saudi Arabia, to howls of protest from Swedish arms exporters. But maybe Charles's mother is doing her bit for the firm's long-term interests. Sovereigns in Spain, Belgium, the Netherlands and the Vatican, all of them considerably younger than the queen, have recently bowed out; you can understand Elizabeth’s reluctance to lob Charles the orb.