It is one of the oddities of the Royal family -- shared by the majority of the English upper classes -- that for many generations they have circumcised their male sons, invariably using a Mohel, the Jewish word for a circumcision practitioner. It was rarely done on medical grounds, nor on religious ones, but was a matter of class.

This has prompted some speculation as to whether the Duke and Duchess of Cambridge will chose to follow suit. Understandably, Clarence House will not comment on such a private and delicate matter.

However, it is unlikely because the connection between class and circumcision, which continued up into the 1970s, has all but died out in Britain. Indeed by the time the Duke of Cambridge himself was born in 1982, it is understood that Diana, Princess of Wales, refused to continue the tradition, in keeping with the then medical opinion that it was an unnecessary procedure whose risks outweighed any possible benefits.

The NHS now tries to guide parents away from the practice and the most recent figures suggest just 3.8 per cent of male babies are circumcised in the UK. This is down from a rate of 20 per cent in the 1950s, when there was a belief, especially among those who could afford to have it done privately, that it was more hygienic.

The Prince of Wales is among the royals who have been circumcised

Nearly all of those now undertaking the practice do so on religious grounds -- it is done by nearly all Muslims and Jews -- as well as a few on cultural grounds.

Maurice Levenson, the secretary of the Initiation Society, an Anglo-Jewish organisation which represents about 55 mohels, said: “The great majority of the enquiries we receive come from those of the Jewish faith, Muslims, Afro-Caribbeans and Americans, where circumcision remains popular.” He said very few upper class British parents approached the organisation as they did in previous decades.

The Portland Hospital, which has the most famous private maternity ward in London, after the Lindo Wing at St Mary's, where Prince George was born, offers circumcision on site for £737.

The connection between circumcision and the royal family was started by George I, who brought the practice over from Hanover. And it has continued through Queen Victoria’s children to Edward VII, and then through the Duke of Windsor to the Prince of Wales, Princes A ndrew and Edward.

Dr Jacob Snowman, the medical officer to the Initiation Society, undertook the act in Buckingham Palace after the Prince of Wales was born. Mr Levenson scotched the finer detail of my dinner party anectdote by pointing out that Dr Snowman senior in fact died at the ripe old age of 88 in 1959, and I was done by his son, Dr Lionel Snowman, also medical officer to the Society, and also mohel of choice to the Chelsea set in the 1960s and 1970s.

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It was the ‘done thing’ in week one of the baby’s life, along with the hiring of a maternity nurse and being put down for Eton and membership of the MCC. My mother recounts that when Dr Snowman arrived at our home, she asked if he needed anything, expecting an answer of “some hot water”. He replied, “a glass of red wine would be nice".

Though the Windsors may have stopped the practice, mohels -- the majority of whom are not doctors -- are still called upon by non-Jewish parents.

Mr Levenson said: "There are many people outside the Jewish community, who call on them for circumcision. Their experience and expertise provides parents with a considerable degree of comfort and reassurance”. Muslims often use mohels.

It remains a popular practice with Americans, including American ex-pats in London, though it is a slightly diminishing trend.

The World Health Organisation back in 2007 estimated that around 30 per cent of males aged 15 and over are circumcised around the world, with almost 70 per cent of these being Muslim.