Tony Blair became Labour's longest continuously serving prime minister on 2 August.
Tony Blair passed record for Labour on 2 August
His years in Number 10 may be a landmark but he has a long way to go if he wants to compete with the longevity of some of his Downing Street predecessors.
Sir Robert Walpole.
Walpole was effectively prime minister - but without the title - for 21 years from 1721-42.
He was the first premier to live and work out of Number 10 Downing Street.
Eton and Cambridge educated he inherited a country estate aged 24 and was able to finance a political career entering Parliament as a Whig MP.
Low points included a six month spell in the Tower of London for accepting an illegal payment when Secretary of War.
He was credited with reducing the national debt and stabilising prices and his longevity in office can in no small part be explained by his popularity with the king.
Another Whig prime minister who held office from 1743 to 1754 - a total of 11 years.
Pelham was a friend of Walpole and served as his Lord of the Treasury.
He led the country during the war of Austrian succession and made a failed attempt to strengthen the rights of British Jews.
The Tory premier ruled for 12 years from 1770 - 1782 having previously been a chancellor of the exchequer.
North was deeply loyal to King George III and was prime minister during the American war of independence which lost the UK its colony.
Although the king himself insisted upon the war, North has been blamed for tactical errors that led to heavy British losses.
North tried to resign but was not allowed to leave Downing Street until after the war.
Pitt the Younger - as he was also known - served as prime minister for 20 years between 1783-1801 and 1804-1806 first taking the top job at the age of 24.
The year before he had served as chancellor and leader of the Commons.
Pitt's earlier years as prime minister were dogged by parliamentary defeats as he tried to water down the influence of the monarchy and tackle corruption.
But his popularity rose over time and, following a huge election victory in 1784, he set about reducing the national debt.
The following year his bid to tackle rotten boroughs and introduce a union with Ireland bill caused him to have a rockier ride.
King George III's mental illness also put his premiership under pressure.
Liverpool's premiership lasted from 1812 until 1827 with his initial rise to power following on from the assassination of Spencer Perceval.
Despite being quiet and private - not characteristics that chime very much with politicians in the modern world - he won four elections and was one of the longest serving prime ministers.
His time in power saw the death of George III and the end of the Napoleonic wars.
The Tory premier was anti-democratic reform and controversially he defended the authorities who carried out the Peterloo massacre.
He quit office after a stroke and in 1827 and died the following year.
Palmerston had two spells in the top job: from 1855-8 and from 1859-65.
He started off as a Tory but his support for Catholic emancipation and parliamentary reform led to his defection to the Whigs.
A long-serving foreign secretary under Earl Grey, Palmerston's somewhat confrontational style led him into occasional difficulties.
He finally lost his job when he mobilised the British navy against Greece in defence of a UK citizen.
His ascent to Number 10 came when he succeeded Lord Aberdeen who was blamed for the disasters of the Crimean war.
Palmerston ended the war and was prime minister for eight years before dying in office aged 80.
Disraeli first became prime minister in 1868 and then once again between 1874 and 1880.
He tried to extend male suffrage to the working classes during the 1860s and was invited to be prime minister by Queen Victoria in 1868.
Tory Disraeli was one half of the greatest political rivalry of that era and one of the greatest parliamentary rivalries of all time competing with Whig leader William Gladstone.
Gladstone had three spells as prime minister: from 1868-74, 1880-85 and 1892-94.
Queen Victoria - who had enjoyed a close relationship with Disraeli - complained that Gladstone addressed her "as though I were at a public meeting".
Gladstone had a tricky relationship with Queen Victoria
The man most Liberals look back to as their hero in fact began life as a Tory opposed to the abolition of slavery and democratic electoral reform.
Gradually his political perspective changed when he became increasingly in favour of free trade and against the protectionism associated with the Tory Party.
His time as chancellor has been credited by many as the moment when that role became central to British governments.
His instincts were tax-lowering although the cost of the Crimean war forced him to reverse his own income tax cuts.
He was also converted to the view that voting rights should be extended to as many men as were deemed fit.
Salisbury took over the Tory Party following Disraeli's death in 1881 and was prime minister between 1885-6, 1886-92 and 1895-1902.
As well as being the last serving prime minister to sit in the House of Lords, Salisbury introduced free primary education and policies aimed at strengthening local government.
Salisbury's tenure saw the dawning of the 20th century during which prime minister ships tended to last much shorter periods.
Liberal Herbert Asquith chalked up eight years in Downing Street and Tory Stanley Baldwin managed just over seven years.
Winston Churchill was prime minister for more than eight years.
Labour's Clement Attlee managed to win two elections and was prime minister for six years.
Thatcher will be remembered as the first woman prime minister and as a leader whose premiership was characterised by controversy.
Dubbed the Iron Lady her time in power saw remarkable change in Britain.
Margaret Thatcher was the first woman prime minister
Battles with the unions, the end of the Cold War and the Falklands crisis were just some of events that took place.
In the end when she left Downing Street - having been prime minister from 1979 until 1990 - she did so because she knew she no longer had the support of her ministers who believed she would lose them the next election.
With Mr Blair hinting on Thursday that he might stay on for a full third term - subject to the consent of the British voter - it is her 11 and a half years are the most obvious target for him to try to beat.