Why ask now?
Have you been hibernating? Because page after page of Britain's newspapers are filled with photographs of the soignée Carla Bruni-Sarkozy, the former Italian supermodel and new wife of the French President, Nicolas Sarkozy, who is in Britain on a state visit.
Details of her elegant grey Christian Dior outfit, with matching beret, have somewhat overwhelmed her husband's announcement that France will increase its troop numbers in Afghanistan and, in a joint initiative with Britain, to put flesh on the promises made at Gleneagles, put 16 million more African children into school.
She comes from a wealthy Italian industrialist family, speaks five languages fluently, and is said to be well versed in French literature and philosophy. Oh, and there have also been the photographs of her naked, her hands covering her lower modesty, leaving her gamine breasts exposed for maximum tabloid titillation.
Where does the idea come from?
From fairy tales and feudalism. If you have a King you need a Queen; if you have a President you must have a First Lady. The actual expression was first used in America in 1849 when Zachary Taylor, the otherwise unmemorable 12th US President, used the term of Dolley Madison, widow of a president, at her state funeral.
What does a First Lady do?
Anything she likes, according to the present incumbent in the White House, Laura Bush. "The role of First Lady is whatever the First Lady wants it to be," she has said. Over the years, First Ladies have been White House managers, renovators and hostesses. More recently they have been campaigners, social activists and policy advocates.
So they do anything they like?
That's not how they all have seen it. "There is something in this great unsocial house which depresses my spirits beyond expression," said Louisa Adams, wife of President John Quincy Adams, in the 1820s. Her successor, Margaret Taylor (wife of Zac above), was so horrified by the prospect that she "prayed mightily" for her husband to lose the election.
Others have fought shy of acknowledging any public role. "I do not belong to the public," said Abraham Lincoln's wife, Mary. "My character is wholly domestic, and the public have nothing to do with it."
Until comparatively recently, First Ladies – like the wives of British prime ministers – saw their primary role as supporting their husbands.
"The major role of the First Lady," said Jackie Kennedy, the wife of the first "modern" US president, in the 1960s, "is to take care of the president so that he can best serve the people." So it has largely continued: "No First Lady need to make apologies for looking out for her husband's personal welfare," said Nancy Reagan. "The First Lady is, first of all, a wife."
But don't they have to be public figures?
Who says so? Look at Mrs Gordon Brown. The one-time PR career girl Sarah Macaulay has all but vanished from the public stage. Unlike her predecessor, Cherie Blair – who tried to be simultaneously a career woman, a private mother and a public hanger on the arm of her husband in his international travels – Sarah Brown stayed at home when her husband went to Camp David. Since her rather nervy appearance at Gordon's side when he arrived in No 10, she has kept herself, and her children, out of camera shot.
There must be more to it than home cooking and buying the right shoes and handbag?
There is the pillow talk. First Ladies have undoubted influence on their husbands, says Rosalynn Carter, wife of President Jimmy, "They talk with them all the time, they have the President's ear. I don't think there is any doubt about it."
Some are blunt about this. "I know what's best for the President. I put him in the White House," said Warren G Harding's wife, Florence. "He does well when he listens to me and poorly when he does not."
Others are more subtle. Laura Bush, a one-time librarian, has particular concerns about Aids, education and Africa. Examine her husband's aid programme and you find that spending on these has increased dramatically.
Others are more direct. Eleanor Roosevelt as First Lady campaigned publicly for human rights, among other things.
But weren't some First Ladies the power behind the throne?
Certainly. Perhaps the most influential American First Lady was Edith Wilson, the second wife of Woodrow Wilson, who after her husband's stroke, took over the White House. She later wrote: "I studied every paper, sent from the different secretaries or senators, and tried to digest and present in tabloid form the things that, despite my vigilance, had to go to the President.
I myself never made a single decision regarding the disposition of public affairs. The only decision that was mine was what was important and what was not." Many historians believe this minimises her influence. She has been variously dubbed "the Secret President" and "the first female president of the United States".
Something similar happened in China in the dying years of Mao Tse Tung. His wife, Jiang Qing, who was known as Madame Mao, led the Cultural Revolution and, during the last years of Mao's life, was her husband's "principal aide".
By the time of his death, she and her cronies controlled nearly all of China's institutions with the authority of a virtual empress. A month after he died, she was arrested and accused of attempting to seize power.
At her trial she defended herself, saying famously: "I was Chairman Mao's dog. Whomever he asked me to bite, I bit". She was jailed and 10 years later allegedly hanged herself in a hospital bathroom at the age of 77.
Were none given formal roles?
Hillary Clinton was, for a time, given an official post in her husband Bill's administration developing reforms to the health care system. It was not a great success.
When Néstor Carlos Kirchner was President of Argentina, a few years back, his wife, Cristina, who had been the backbone of her husband's campaign for the presidency in 2003, became an itinerant ambassador for his government. Her style was highly combative, in the manner of a previous First Lady, Eva Perón. Like Perón, she succeeded her husband as president under the title Cristina Elizabet Fernández de Kirchner. Hubby is now Argentina's "First Gentleman".
Are First Ladies an asset to their husbands or their nation?
* They keep their husbands grounded in the reality of daily living
* They input an alternative perspective into high-testosterone politics
* They divert attention from the policy decisions their husbands make
* They are a remnant of time when women were subservient
* Their past can come back to haunt their husband
* They divert attention from the policy decisions their husbands makeReuse content