Lord Russell was 56 when his fourth son was born. Few premiers have been as young as Tony Blair, who was four days short of his 44th birthday when he took office in May 1997, making him the youngest Prime Minister since 1812 when the Earl of Liverpool moved into Downing Street, aged 42.
Only Henry Herbert Asquith, who became Prime Minister as leader of the Liberal Party in 1908, had children as young as the Blairs when he moved into Number 10. His two children were Anthony, five, known as Puffin, and Elizabeth 11.
Nearly all of Mr Blair's predecessors have been of the age where their children, if they had any, were adults or in their late teens. John Major's son James, at 15, was well into his secondary school education when his father became premier in 1990.
James was of an age where his performance on the school football field became of interest to the media. Mr Major's less well known daughter, Elizabeth, was 18.
Baroness Thatcher's twins, Mark and Carol, were 25 when their mother became the country's first woman Prime Minnister in 1979.
The only thing known to have made the Iron Lady weep, other than having to leave office, was her son Mark and his attractive female co-driver be-coming lost during a desert rally in Africa.
The last celebrated occasion when a baby belonging to a prime ministerial family entered Downing Street was in 1989 when Margaret Thatcher, as she then was, greeted her grandson, Michael, for the first time. When the baby, Mark's child, was born a few weeks earlier, Mrs Thatcher said : "We are a grandmother."
The Prime Minister was being interviewed when Mark and the baby arrived at Number 10. Her press secretary, Sir Bernard Ingham, shouted to her: "Your grandson's here."
At that, Mrs Thatcher rushed out of the room, down the stairs and out into the street where she held him for the first time.
Photographs were taken in Downing Street and then inside Number 10. Lady Thatcher now has two grandchildren.Reuse content