1 Winston Churchill, Conservative, 1940-45 and 1951-55 As the war took hold of Europe, Britain turned to a naval man with a fierce patriotism and fiery rhetoric to lead the coalition Government. In his first speech to Parliament as Prime Minister he said: “I have nothing to offer but blood, toil, tears and sweat.” He presided over Allied victory in the Second World War, meaning that a lacklustre second term did nothing to diminish his status as a national hero.
2 David Lloyd George, Liberal, 1916-1922 The only Prime Minister to date whose first language was not English (he spoke Welsh), Lloyd George was hailed by the public as the “man who won the war”. He was prominent on the world stage, representing Britain at the Versailles conference. Lloyd George was also a radical and one of the architects of the welfare state. He supported women’s suffrage, raising taxes and implementing social reform. His tenure also saw the creation of the Irish Free State and the Balfour Declaration that supported the establishment of Israel.
3 William E. Gladstone, Liberal, 1868-74, 1880-85, 1886 and 1892-4 One of the great Victorian statesmen with a penchant for political grudges and “rescuing” prostitutes, Gladstone came close to succeeding in his mission to bring Home Rule to Ireland. He sometimes struggled to control an unruly party but eventually he managed to pass the Third Reform Act, tripling the British electorate by extending the vote to labourers and paving the way for full male suffrage. As Chancellor, he displayed his eye for detail by delivering an eye-watering Budget speech that lasted a record 4 hours and 45 minutes.
4 William Pitt, the Younger, Tory, 1783-01, 1804-06 Pitt, the younger, famously followed in his father’s footsteps by becoming Prime Minister at the tender age of 24. His time in office was dogged by clashes with his great parliamentary rival, Charles Fox, and the growing madness of King George III. Pitt’s lengthy career was an eventful one, encompassing wars with France, the Act of Union at home and the reduction of the national debt. Although you can now blame Pitt for Britain’s first income tax, he was increasingly popular in his time. He died, aged 46, uttering these last words: “Oh my country! How I love my country!” 
5 Margaret Thatcher, Conservative, 1979-1990 Thatcher was the first female Prime Minister in Europe and hers was the longest uninterrupted period in office since the 1820s. She was elected to end the economic crisis of the 1970s but the sometimes harsh impact of her reforms, including the poll tax, alienated parts of the country. Although she was a polarising politician, the Iron Lady remained popular with much of the electorate. Her downfall was brought about by in fighting within the Conservative Party, particularly over Europe. Her economic reforms were largely accepted by new Labour.
6 Sir Robert Peel, Conservative, 1834-35 and 1841-46 Peel was the founder of the Conservative Party. His epoch-defining Tamworth Manifesto reinvented conservative values for the new middle-class electorate. Before rising to Prime Minister he passed the Metropolitan Police Act, setting up London’s first disciplined police force who were known as “bobbies” in his honour. Law and order and a strict system of taxation became central to his brand of politics. When Peel resigned the Cabinet was split and his fledgling party was divided over the protectionist Corn Laws, which he had repealed.
7 Clement Atlee, Labour, 1945-1951 The founder of the modern welfare state was elected after the Second World War with a clear mandate to change British society. Atlee appointed a Cabinet that did just that, creating the National Health Service, nationalising utilities, the rail network and the Bank of England.
8 Earl Grey, Whig, 1830-34 Had a blend of tea named after him — nobody quite knows why. He also presided over one of the most transformative governments in British history. He enacted the Reform Act 1832, which greatly increased the electorate, turning the middle classes into voters and destroying the “rotten boroughs”. A year later he abolished slavery throughout the Empire.
9 Robert Walpole, Whig, 1721-42First Lord of the Treasury and Chancellor of the Exchequer for more than 20 years, he was known as the First Minister and is generally regarded as the original Prime Minister. Walpole had plenty of enemies but his policies of avoiding war and imposing low taxes were popular throughout a period in office where the House of Commons grew in influence compared to the monarchy and the House of Lords. King George II gave No 10 Downing Street to Walpole. He refused to accept it as a personal gift but accepted it as the official residence of the First Lord of the Treasury.
10 Benjamin Disraeli, Conservative, 1868, 1874-80 Disraeli was one of the first true party politicians. His personal enmity for William Gladstone helped shape modern partisan politics. “I have climbed to the top of a greasy pole,” he told a friend on his appointment as leader of the Conservative Party. As Prime Minister he introduced progressive legislation to safeguard the rights of the working classes. He found the time to write 17 novels, although none of them were terribly good.
11= H.H. Asquith, Liberal, 1908-1916 Asquith’s name remains synonymous with a time of great social change in Britain. During his tenure, pensions and national insurance were introduced. But his premiership was also overshadowed by an arms race with Germany and the beginning of the First World War. He became the first politician to regularly use radio recordings to communicate with the British people. He was a staunch Liberal who continued to lead the party even when he lost his parliamentary seat.
11= The Marquess of Salisbury, Conservative, 1885-86, 1886-92 and 1895-1902 Robert Cecil was Foreign Secretary as well as Prime Minister through long periods of aggressive expansion of the British Empire. He was a vigorous actor in the scramble for Africa and an ardent believer in the civilising force of colonialism. Although he was busy militarily and diplomatically he operated a policy of Splendid Isolation choosing not to form alliances with other nations.
14 Stanley Baldwin, Conservative, 1923-1924, 1924-1929, 1935-1937 Stanley Baldwin kept the Downing Street removal men busy during his lengthy political career. Having given a fifth of his wealth to help British efforts in the First World War, he went on to champion democracy in the post-war years. Baldwin’s most sensitive task involved managing the abdication of King Edward VIII over the Wallis Simpson affair. He also oversaw the introduction of female suffrage and rearmament before the Second World War.
15 Harold Macmillan, Conservative, 1957-63 “Supermac” presided over the “wind of change” that curtailed the British Empire. He also strengthened Britain’s nuclear deterrent and rebuilt the special relationship with the US. He resigned suddenly because of ill health while the nation was struggling with the balance of payments and the Conservative Party was rocked by the Profumo scandal.
16= Tony Blair, Labour, 1997-2007 After 18 years in opposition the Labour Party was rebranded by Blair, who ditched some of the party’s traditional policies. “Teflon Tony” won three elections, two by a landslide, and introduced a minimum wage and constitutional reform, and signed the Good Friday power-sharing agreement in Northern Ireland. Record-breaking popularity gave way to approval ratings as low as 23 per cent as the end of his premiership became dominated by the Iraq war, a close relationship with President Bush and the cash-for-honours scandal.
16= The Earl of Chatham, Whig, 1766-68 Although his most famous achievement may have been fathering William Pitt, the Younger, William Pitt, the Elder, was immensely powerful in his own right. His most influential acts came before he became Prime Minister. The Earl of Chatham, another moniker, is often credited with overseeing the expansion of the British Empire. At home he brought down Robert Walpole and seized control of military manoeuvres in Europe. Eloquent and extremely popular with the public, he never lacked confidence. He once said to a colleague: “My Lord, I am sure I can save this country, and no one else can.”
18 Earl of Derby, Conservative, 1852, 1858-59 and 1866-68 Edward Smith-Stanley is the longest-serving leader of the Conservative Party and his three stints as Prime Minister lasted a total of four years. Although his political achievements were real — not least in holding his party together — and he was known as a great orator, he always suffered in comparison with his rival and contemporary Disraeli. His reform Bill of 1867 effectively doubled the franchise.
19 Earl of Liverpool, Tory, 1812-27 Liverpool governed during the period of radicalism that followed the Napoleonic Wars. He was often criticised for using repressive measures but largely succeeded in maintaining stability in a period of Europe-wide unrest. In these early decades of the 19th century Britain was in massive debt and disabled by bad harvests and a recession. He was ably assisted by a skilled Cabinet, whose members included Robert Peel and the Duke of Wellington. Hugely unpopular during the Peterloo Massacre and Corn Laws, he became increasingly well-liked towards the end of his time in office. Liverpool Street is named after him.
20 Harold Wilson, Labour, 1964-70 and 1974-76 Wilson won four general elections and served two stints at No 10, steering Britain through the latter half of the Swinging Sixties and the rapid social change that it brought. Although tactically and politically astute, the pipe-smoking former Oxford don never quite got to grips with the country's bigger economic problems and shocked the nation with his abrupt resignation in March 1976, just days after his 60th birthday.
21 Lord Russell, Whig, 1846-52 and 1865-66 A progressive liberal, Russell rose to national prominence as a key architect of the Reform Act 1832 that gave the vote to the middle classes. As Prime Minister, however, he struggled to deal with the turbulent period of European revolutions and the Irish potato famine. In a second futile stint in office he tried but failed to introduce further democratic reform and could not keep his party united.
22 Henry Campbell-Bannerman, Liberal, 1905-1908 The first Downing Street resident to use “Prime Minister” as a title, Campbell-Bannerman spent 40 years of his life in Parliament. He came to power shortly after the Boer War, which he had opposed. A fierce champion of free trade, he is also credited with holding the Liberal Party together in a period of dissention. Campbell-Bannerman became the first Prime Minister to die in No 10, despite having handed over to H.H. Asquith three weeks previously. His last words proved somewhat over-ambitious: “This is not the end of me,” he said.
23 Ted Heath, Conservative, 1970-74 Heath’s time at No 10 was bookended by Harold Wilson's two stints. This era in British politics encompassed decimalisation, UK accession to the European Economic Community and the 1973 oil crisis. That was followed by the seven-week miners' strike and Three Day Week, events that contributed to Heath's election defeat.
24 Duke of Wellington, Tory, 1828-30 and 1834 The Iron Duke led the Allied army to victory over Napoleon at the Battle of Waterloo as a commander. He returned to politics in London where he tried to stand firm against the reformists but he was forced to watch in horror as the Reform Act was passed between his two conservative stints in office.
25 Viscount Melbourne, Whig, 1834 and 1835-41 William Lamb, 2nd Viscount Melbourne, was the last PM sacked by the monarch when William IV took offence at the Whigs' plans for reform of the Church in 1834. His would-be Tory successor, Robert Peel, could not win a parliamentary majority and Melbourne's second stint in office was longer, lasting from 1835 to 1841. Although he was a reformer, Melbourne is best remembered for his close relationship with Queen Victoria, to whom he became a virtual father figure after she assumed the throne in 1837. The closeness of their relationship became a political issue — the “Bedchamber Crisis". Fittingly, the state capital of Victoria, in southern Australia, was named after him.
26 Earl of Shelburne, Whig, 1782-83 At a time of global war Shelburne was most notable for his desire to bring peace. He was particularly conciliatory towards America, refusing to accept a government role until the new country had been officially recognised. Shelburne’s reputation has grown since his death and many believe that his reforming instinct would have brought great changes had he stayed in office longer.
27 James Callaghan, Labour, 1976-79 Callaghan became Prime Minister halfway through an electoral term, with Labour attempting to govern without a parliamentary majority and under pressure from the trade unions. He proved surprisingly adept at managing this difficult position and picked up the nickname Sunny Jim. After deciding against a snap election in late 1978 to maximise his popularity, the Winter of Discontent intervened and the Government was brought down after a vote of no confidence in March 1979.
28 John Major, Conservative, 1990-1997 Major inherited an economy in crisis and handed over a far more stable situation but his reputation was terminally damaged by the humiliation of Black Wednesday, when the UK was forced out of the European Exchange Rate Mechanism. Faced with the task of following Margaret Thatcher, Major won the 1992 election surprisingly comfortably but sleaze and disunity left the Conservative Party virtually unelectable five years later.
29 Henry Pelham, Whig, 1743-54Pelham stood up to King George II, who was in favour of deeper involvement in a conflict with France and Prussia. He resigned along with all of his ministers forcing the King to back down and re-appoint him. Pelham was credited with restructuring the nation’s finances. Together with his brother, the Duke of Newcastle, who succeeded him as Prime Minister, he managed a vast web of influence and power.
30 Arthur James Balfour, Conservative, 1902-05Made progress in Ireland, despite his “Bloody Balfour” reputation, and signed the Entente Cordial with France but he was unable to find a satisfactory compromise between tariffs and free trade and resigned as the head of a divided party.
32 Marquess of Rockingham, Whig, 1765-66, 1782The political career of Rockingham was inextricably linked with the American Revolution. During his first stint as Prime Minister, he repealed the controversial US Stamp Tax but it was too late — the damage had been done. His second period in office saw the opening of peace negotiations with the newly independent America. Rockingham had an ambitious plan for social reform but died 14 weeks after becoming Prime Minister for the second time.
33 Ramsay MacDonald, Labour/National Government, 1924 and 1929-35 MacDonald was the first Labour Prime Minister but no hero of the party. After an abortive first term he was given a second chance to lead a minority Labour Government before splitting with the party and spending four years as the head of a National Government. MacDonald was effectively no more than the figurehead of a coalition dominated by the Conservatives. In reality, future prime ministers Stanley Baldwin and Neville Chamberlain were responsible for guiding Britain through the Great Depression.
34 Andrew Bonar Law, Conservative, 1922-1923Nicknamed the “Unknown Prime Minister”, Law did not even make it through a year in office. He had worked closely with the Liberals and Lloyd George during a wartime coalition, but when members of his own party threatened to defect to the Liberals he gave a rousing speech at the Carlton Club to prevent the split. He lost two sons in the First World War but his plans to help Britain recover from the conflict were undone when he was forced to resign because of ill health.
35 Neville Chamberlain, Conservative/National Government, 1937-40 Popularity in contemporary political circles and some domestic success could not save Chamberlain’s reputation. To most people he is forever associated with one dreaded word: appeasement. There was to be no “peace with honour” after his return from a meeting with Adolf Hitler and Benito Mussolini waving the Munich Agreement.
36= Spencer Perceval, Tory, 1809-12The Napoleonic Wars and Industrial Revolution were the backdrop to Perceval's political career. A lawyer by training, he opposed Catholic emancipation and prosecuted radicals. During a time of political schisms, Perceval had to serve as his own Chancellor after six other men refused the office. He is best known for his abrupt end. The Tory was shot in the lobby of the House of Commons, making him the only British Prime Minister to be assassinated.
36= Alec Douglas-Home, Conservative, 1963-64A member of the House of Lords and a first-class cricketer, Douglas-Home was chosen to replace Harold Macmillan. He had one year to try to save the Conservatives, who were torn apart by the Profumo scandal, but he could not prevent defeat by Harold Wilson in 1964.
36= Gordon Brown, Labour, 2007-After a decade as Chancellor, presiding over the economic boom that helped Tony Blair to maintain his popularity, Brown finally moved into No 10 and watched the nation’s finances crumble along with his reputation. He attempted to style himself as the world’s Chancellor with high-profile domestic and global fiscal stimulus initiatives in response to an international economic crisis. Early domestic popularity, encapsulated in the “Not flash, just Gordon” slogan, faded amid accusations of Labour spin and dishonesty.
39= Duke of Portland, Whig, 1783, 1807-09Twenty years passed between the Duke of Portland’s two periods in office as Prime Minister. His first term was dominated by an attempt to limit the power of the East India Company. Over the next two decades, Portland observed the French Revolution, the Napoleonic Wars and the expansion of the British Empire. When his turn came round again he was effectively a puppet Prime Minister, chosen to head a deeply divided Government. He was able to do little more than watch as his ministers bickered and, in the infamous case of Viscount Castlereagh and George Canning, shot at one another.
39= Henry Addington, Tory, 1801-04Known as the “doctor”, Addington had a powerful supporter in King George III, whom he had treated for a bout of madness. His biggest achievement as Prime Minister was negotiating the short-lived Treaty of Amiens with France in 1802. But his reputation crumbled in later years when he suspended habeas corpus as Home Secretary. His most visible legacy remains the defensive Martello towers that dot the British coast.
41 Duke of Newcastle, Whig, 1754-6 and 1757-62Thomas Pelham followed his brother Henry as Prime Minister. He resigned his first term after two years when the Seven Years' War against France appeared to be going badly. In his second period in office he was forced into an uneasy alliance with William Pitt, the Elder, whom he hated. He resigned after Pitt brilliantly turned defeat into victory in the war against France.
42 Earl of Aberdeen, Whig/Peelite coalition, 1852-55George Hamilton-Gordon was orphaned at 11 and raised by his guardian William Pitt the Younger. He was made an Earl, a Viscount and a Lord before becoming Prime Minister. The self-styled Lord Haddo resigned after leading Britain into the Crimean War against Russia, a disastrous conflict that could have been avoided altogether.
43 Lord Grenville, Whig, 1806-07William Wyndham Grenville was a cousin of William Pitt, the Younger, and the son of George Grenville, who had been Prime Minister in the mid-18th century. He only lasted a single year in the job. After falling out with King George III over the Catholic Relief Bill, he was sacked.
44 Duke of Devonshire, Whig, 1756-57The Duke of Devonshire much preferred horse racing and society to the rigours of political office. Founder of the Jockey Club, he was known as one of London’s best-looking men. His brief period as Prime Minister was really a chance for William Pitt, the Elder, to pull the strings.
45 The Earl of Rosebery, Liberal, 1894-95Archibald Primrose, the 5th Earl of Rosebery, famously listed three ambitions: to marry an heiress, own the winner of the Epsom Derby and become Prime Minister. In the event he married a Rothschild and sent out winners in all five Classics, including three Derbies. He also became Prime Minister, but lasted just 15 months before engineering his own departure through an unnecessary confidence vote. He need not detain us further.
46 The Earl of Bute, Tory, 1762-63The arrival of the first Scottish Prime Minister spelled the end of a long period of Whig domination. Bute had been King George III's tutor when he was still a boy. Bute was unpopular, largely because of his Scottish roots, and only survived for 11 months. Perhaps his best-known legacy was the creation of the Kew Gardens botanical park in West London.
47 Anthony Eden, Conservative, 1955-57A soldier in the First World War and Foreign Secretary during the Second World War, Eden seemed the perfect man to take over after Winston Churchill’s retirement. His disastrous miscalculation over the Suez Canal lost most of his political capital, if not his public popularity, and he retired, citing ill health, a month after the crisis had ended.
48 Lord George Grenville, Whig, 1763-65 Lord Grenville’s two years as Prime Minister were marked more by his failures than his successes. Of these, losing the American colonies ranks high on the list. The Stamp Tax introduced by his short-lived Government in 1765 provided the catalyst for the War of Independence. Mocked as the “Gentle Shepherd”, Grenville became deeply unpopular with the public after he prosecuted John Wilkes for libelling the King. He then argued with George III himself, effectively ending his political career.
49 The Duke of Grafton, Whig, 1768-70 The Duke of Grafton was a tabloid dream. Both he and his wife were known for their indiscretions. He also revelled in his mysterious nickname “The Turf Macaroni”. His political career was short and marked by the American revolt. He was brought down by the anonymous letters from “Junius” who attacked him in the press.
50 Lord North, Tory, 1770-82Lord North’s twelve years in office were not successful ones. He led Britain into the American War of Independence and approved some of the most disastrous military strategies of the conflict. North tried hard to resign but George III refused to permit it until the conclusion of the war. He then suffered the ignominy of being voted out in the first ever motion of no confidence. North’s efforts at home were no better than abroad. His decision to ban Catholics from the military provoked anti-Catholic riots in London.