Sarah Brown, with husband Gordon, as they arrive at Number 10
With Cherie Blair now having departed Downing Street with husband Tony, it is time to meet the UK's new "first lady". Step forward Sarah Brown.
Like Mrs Blair, Sarah Brown is a highly intelligent woman who has reached the top in her chosen field.
But that is probably where the similarity ends.
She has always enjoyed a lower profile than Cherie - and unlike Mrs Blair has never appeared to entertain political ambitions of her own.
As a public relations executive, she appears to understand the value of discretion and seems content to remain in a background, supporting role.
Unlike Cherie - who uses her maiden name Booth professionally - Sarah is always Sarah Brown - she dropped Macaulay the day she got married to the then chancellor.
But despite her low-key approach, she has already become a familiar sight at his side, watching him with evident pride as he delivered his first speech as prime minister outside Downing Street.
She joins Samantha Cameron, a director of Bond Street stationery firm Smythson, and Lady Elspeth Campbell as a member of the party leaders' wives club.
And as such she will find it difficult to avoid the spotlight altogether - even if in the UK the spouse of the leader does not have the same official status of first lady as US presidents' wives have.
Sarah Macaulay was born in 1963 to a Scottish father who worked in publishing and mother who was a teacher.
She spent much of her early childhood in Tanzania, moving to London to live with her mother when her parents separated.
Sarah Brown with her husband on the day he became Labour leader
She attended Acland Burghley comprehensive school in Tufnell Park and later went to Camden High School for Girls.
She then studied psychology at Bristol University and moved into design and communications after gaining her degree.
It was through the public relations company she set up with school friend Julia Hobsbawm - Hobsbawm Macaulay Communications - that she met her future husband while organising Labour events.
At that time, in the mid-1990s, Mr Brown was a bachelor who appeared to many people to have little time in his life for anything but politics. But friends from the time said they immediately seemed a good match.
She had strong ideas on the role of women in politics and in particular how their numbers could be boosted in the House of Commons.
She was one of the first 75 women invited to sign a banner to mark the launch of Emily's List, the campaign to raise money to boost female representation at Westminster.
Sarah and Gordon began seeing each other, with early dates including drinks in the private members' club Soho House, but they were anxious to remain out of the glare of publicity.
Sarah was credited with smartening up Mr Brown's image but it was not until the eve of Gordon Brown's first Budget, in 1997, that their relationship was made public, when Mr Brown's spin doctor Charlie Whelan arranged for them to be photographed dining together at a Soho restaurant.
In 1998, then deputy prime minister John Prescott got up on stage at Labour's annual conference and said: "Gordon, forget prudence and name a date for Sarah. She's a lovely lass."
But it would be another two years before they were married at a modest ceremony at Mr Brown's constituency home in Fife.
Sarah has appeared on the campaign trail with her husband but has tended to concentrate on her family and charity work.
When she became pregnant with the couple's first child she left her company, once ranked among the UK's top 50 PR firms.
The Browns' daughter, Jennifer Jane, was born seven weeks early.
Tragically, she suffered a brain haemorrhage and died in her parents' arms after 10 days.
In their daughter's memory Mrs Brown founded a charity, Piggy BankKids, which helps disadvantaged children. She also established the Jennifer Brown Research Fund, named after the baby, in 2002 to help research into pregnancy difficulties.
She supports the National Council for One-Parent Families, including writing the introduction to a short story collection for the campaign group in 2002. Her friend and Harry Potter author JK Rowling wrote the foreword.
She is also patron of domestic violence charity Women's Aid, Maggie's Cancer Caring Centre, and educational charity Shine.
The Browns went on to have two sons, John, born in 2003, and Fraser, who was diagnosed with cystic fibrosis shortly after his birth last year.
Mrs Brown has never given an interview about her family or home life but Mr Brown has spoken warmly of his two young sons.
"Obviously, we've had difficulties with Fraser, but I hope he's going to come through all that. It's incredible having two lively young children who are doing so well," he recently told a newspaper.
Sarah Brown is expected to remain out of the limelight and concentrate on her family and charity work.
"It's the man she loves, rather than the job," her friend, the newspaper columnist Mariella Frostrup, recently commented.