George III was the most attractive of the Hanoverian monarchs. He was a good family man (there were 15 children) and devoted to his wife, Charlotte of Mecklenburg-Strelitz, for whom he bought the Queen's House (later enlarged to become Buckingham Palace).
However, his sons disappointed him and, after his brothers made unsuitable secret marriages, the Royal Marriages Act of 1772 was passed at George's insistence. (Under this Act, the Sovereign must give consent to the marriage of any lineal descendant of George II, with certain exceptions.)
Being extremely conscientious, George read all government papers and sometimes annoyed his ministers by taking such a prominent interest in government and policy.
His political influence could be decisive. In 1801, he forced Pitt the Younger to resign when the two men disagreed about whether Roman Catholics should have full civil rights. George III, because of his coronation oath to maintain the rights and privileges of the Church of England, was against the proposed measure.
One of the most cultured of monarchs, George started a new royal collection of books (65,000 of his books were later given to the British Museum, as the nucleus of a national library) and opened his library to scholars.
In 1768, George founded and paid the initial costs of the Royal Academy of Arts (now famous for its exhibitions).
He was the first king to study science as part of his education (he had his own astronomical observatory), and examples of his collection of scientific instruments can now be seen in the Science Museum.
George III also took a keen interest in agriculture, particularly on the crown estates at Richmond and Windsor, being known as 'Farmer George'.
In his last years, physical as well as mental powers deserted him and he became blind.
He died at Windsor Castle on 29 January 1820, after a reign of almost 60 years - the second longest in British history.
GEORGE IV (r. 1820-30)
George IV was 48 when he became Regent in 1811, as a result of the illness of his father, George III.
He had secretly and illegally married a Roman Catholic, Mrs Fitzherbert. In 1795 he officially married Princess Caroline of Brunswick, but the marriage was a failure and he tried unsuccessfully to divorce her after his accession in 1820 (Caroline died in 1821). Their only child Princess Charlotte died giving birth to a stillborn child.
An outstanding, if extravagant, collector and builder, George IV acquired many important works of art (now in the Royal Collection), built the Royal Pavilion at Brighton, and transformed Windsor Castle and Buckingham Palace. George's fondness for pageantry helped to develop the ceremonial side of monarchy.
After his father's long illness, George resumed royal visits; he visited Hanover in 1821 (it had not been visited by its ruler since the 1750s), and Ireland and Scotland over the next couple of years.
Beset by debts, George was in a weak position in relation to his Cabinet of ministers. His concern for royal prerogative was sporadic; when the Prime Minister Lord Liverpool fell ill in 1827, George at one stage suggested that ministers should choose Liverpool's successor.
In 1829, George IV was forced by his ministers, much against his will and his interpretation of his coronation oath, to agree to Catholic Emancipation. By reducing religious discrimination, this emancipation enabled the monarchy to play a more national role.
George's profligacy and marriage difficulties meant that he never regained much popularity, and he spent his final years in seclusion at Windsor, dying at the age of 67.
WILLIAM IV (r. 1830-37)
William IV was the third son of George III and the brother of George IV.
At the age of 13, William became a midshipman and began a career in the Royal Navy. In 1789, he was made Duke of Clarence. He retired from the Navy in 1790.
Between 1791 and 1811 he lived with his mistress, the actress Mrs Jordan, and the growing family of their children known as the Fitzclarences. William married Princess Adelaide of Saxe-Meiningen in 1818, but their children died in infancy.
William became heir apparent at the age of 62 when his older brother died.
William's reign (reigned 1830-37) was dominated by the Reform crisis, beginning almost immediately when Wellington's Tory government (which William supported) lost the general election in August 1830.
Pledged to parliamentary reform, Grey's Whig government won a further election which William had to call in 1831 and then pushed through a reform bill against the opposition of the Tories and the House of Lords, using the threat of the creation of 50 or more peers to do so.
The failure of the Tories to form an alternative government in 1832 meant that William had to sign the Great Reform Bill. Control of peerages had been used as a party weapon, and the royal prerogative had been damaged.
The Reform Bill abolished some of the worst abuses of the electoral system (for example, representation for so called 'rotten boroughs', which had long ceased to be of any importance, was stopped, and new industrial towns obtained representation).
The Reform Act also introduced standardised rules for the franchise (different boroughs had previously had varying franchise rules) and, by extending the franchise to the middle classes, greatly increased the role of public opinion in the political process.
William understood the theory of the more limited monarchy, once saying 'I have my view of things, and I tell them to my ministers. If they do not adopt them, I cannot help it. I have done my duty.'
William died a month after his niece, Victoria, had come of age, thus avoiding another regency.
VICTORIA (r. 1837-1901)
Victoria was born at Kensington Palace, London, on 24 May 1819. She was the only daughter of Edward, Duke of Kent, fourth son of George III. Her father died shortly after her birth and she became heir to the throne because the three uncles who were ahead of her in succession - George IV, Frederick Duke of York, and William IV - had no legitimate children who survived.
Warmhearted and lively, Victoria had a gift for drawing and painting; educated by a governess at home, she was a natural diarist and kept a regular journal throughout her life. On William IV's death in 1837, she became Queen at the age of 18.
Queen Victoria is associated with Britain's great age of industrial expansion, economic progress and, especially, empire. At her death, it was said, Britain had a worldwide empire on which the sun never set.
In the early part of her reign, she was influenced by two men: her first Prime Minister, Lord Melbourne, and her husband, Prince Albert, whom she married in 1840. Both men taught her much about how to be a ruler in a 'constitutional monarchy' where the monarch had very few powers but could use much influence.
Albert took an active interest in the arts, science, trade and industry; the project for which he is best remembered was the Great Exhibition of 1851, the profits from which helped to establish the South Kensington museums complex in London.
Her marriage to Prince Albert brought nine children between 1840 and 1857. Most of her children married into other Royal families of Europe.
Edward VII (born 1841), married Alexandra, daughter of Christian IX of Denmark. Alfred, Duke of Edinburgh and of Saxe-Coburg and Gotha (born 1844) married Marie of Russia. Arthur, Duke of Connaught (born 1850) married Louise Margaret of Prussia. Leopold, Duke of Albany (born 1853) married Helen of Waldeck-Pyrmont.
Victoria, Princess Royal (born 1840) married Friedrich III, German Emperor. Alice (born 1843) married Ludwig IV, Grand Duke of Hesse and by Rhine. Helena (born 1846) married Christian of Schleswig-Holstein. Louise (born 1848) married John Campbell, 9th Duke of Argyll. Beatrice (born 1857) married Henry of Battenberg.
Victoria bought Osborne House (later presented to the nation by Edward VII) on the Isle of Wight as a family home in 1845, and Albert bought Balmoral in 1852.
Victoria was deeply attached to her husband and she sank into depression after he died, aged 42, in 1861. She had lost a devoted husband and her principal trusted adviser in affairs of state. For the rest of her reign she wore black.
Until the late 1860s she rarely appeared in public; although she never neglected her official Correspondence, and continued to give audiences to her ministers and official visitors, she was reluctant to resume a full public life.
She was persuaded to open Parliament in person in 1866 and 1867, but she was widely criticised for living in seclusion and quite a strong republican movement developed.
Seven attempts were made on Victoria's life, between 1840 and 1882 - her courageous attitude towards these attacks greatly strengthened her popularity.
With time, the private urgings of her family and the flattering attention of Benjamin Disraeli, Prime Minister in 1868 and from 1874 to 1880, the Queen gradually resumed her public duties.
In foreign policy, the Queen's influence during the middle years of her reign was generally used to support peace and reconciliation. In 1864, Victoria pressed her ministers not to intervene in the Prussia-Austria-Denmark war, and her letter to the German Emperor (whose son had married her daughter) in 1875 helped to avert a second Franco-German war.
On the Eastern Question in the 1870s - the issue of Britain's policy towards the declining Turkish Empire in Europe - Victoria (unlike Gladstone) believed that Britain, while pressing for necessary reforms, ought to uphold Turkish hegemony as a bulwark of stability against Russia, and maintain bi-partisanship at a time when Britain could be involved in war.
Victoria's popularity grew with the increasing imperial sentiment from the 1870s onwards. After the Indian Mutiny of 1857, the government of India was transferred from the East India Company to the Crown with the position of Governor General upgraded to Viceroy, and in 1877 Victoria became Empress of India under the Royal Titles Act passed by Disraeli's government.
During Victoria's long reign, direct political power moved away from the sovereign. A series of Acts broadened the social and economic base of the electorate.
These acts included the Second Reform Act of 1867; the introduction of the secret ballot in 1872, which made it impossible to pressurise voters by bribery or intimidation; and the Representation of the Peoples Act of 1884 - all householders and lodgers in accommodation worth at least £10 a year, and occupiers of land worth £10 a year, were entitled to vote.
Despite this decline in the Sovereign's power, Victoria showed that a monarch who had a high level of prestige and who was prepared to master the details of political life could exert an important influence.
This was demonstrated by her mediation between the Commons and the Lords, during the acrimonious passing of the Irish Church Disestablishment Act of 1869 and the 1884 Reform Act.
It was during Victoria's reign that the modern idea of the constitutional monarch, whose role was to remain above political parties, began to evolve. But Victoria herself was not always non-partisan and she took the opportunity to give her opinions, sometimes very forcefully, in private.
After the Second Reform Act of 1867, and the growth of the two-party (Liberal and Conservative) system, the Queen's room for manoeuvre decreased. Her freedom to choose which individual should occupy the premiership was increasingly restricted.
In 1880, she tried, unsuccessfully, to stop William Gladstone - whom she disliked as much as she admired Disraeli and whose policies she distrusted - from becoming Prime Minister. She much preferred the Marquess of Hartington, another statesman from the Liberal party which had just won the general election. She did not get her way.
She was a very strong supporter of Empire, which brought her closer both to Disraeli and to the Marquess of Salisbury, her last Prime Minister.
Although conservative in some respects - like many at the time she opposed giving women the vote - on social issues, she tended to favour measures to improve the lot of the poor, such as the Royal Commission on housing. She also supported many charities involved in education, hospitals and other areas.
Victoria and her family travelled and were seen on an unprecedented scale, thanks to transport improvements and other technical changes such as the spread of newspapers and the invention of photography. Victoria was the first reigning monarch to use trains - she made her first train journey in 1842.
In her later years, she almost became the symbol of the British Empire. Both the Golden (1887) and the Diamond (1897) Jubilees, held to celebrate the 50th and 60th anniversaries of the queen's accession, were marked with great displays and public ceremonies. On both occasions, Colonial Conferences attended by the Prime Ministers of the self-governing colonies were held.
Despite her advanced age, Victoria continued her duties to the end - including an official visit to Dublin in 1900. The Boer War in South Africa overshadowed the end of her reign. As in the Crimean War nearly half a century earlier, Victoria reviewed her troops and visited hospitals; she remained undaunted by British reverses during the campaign: 'We are not interested in the possibilities of defeat; they do not exist.'
Victoria died at Osborne House on the Isle of Wight, on 22 January 1901 after a reign which lasted almost 64 years, the longest in British history.
She was buried at Windsor beside Prince Albert, in the Frogmore Royal Mausoleum, which she had built for their final resting place. Above the Mausoleum door are inscribed Victoria's words: 'farewell best beloved, here at last I shall rest with thee, with thee in Christ I shall rise again'.