In 1714 the Stuart dynasty came to an end with the death of Queen Anne. She was succeeded by the Elector of Hanover, a German prince descended from James I of England; he came to the throne as George I. Not much interested in Britain, George I did not even bother to learn English. He permitted his cabinet ministers to govern—especially Sir Robert Walpole, who became in effect Britain's first prime minister (although the title was not yet in use). Stuart supporters, called Jacobites, attempted unsuccessfully to unseat George I in favor of the son of James II, James Francis Edward Stuart, known later as the “Old Pretender.”

In 1720 Britain was shaken by a financial crisis, known as the South Sea Bubble, brought on by the collapse of a speculative boom in Spanish-American trade. The emergency brought Walpole to power. His wise leadership kept him there for 20 years and established the Whigs as the dominant political party for the next half century.

George I was succeeded in 1727 by his son, George II. Walpole led the government, and Britain was prosperous and virtually at peace. The occasional fighting with Spain was ended by treaty in 1729. British commercial interest turned again toward South America, bringing on the War of Jenkins' Ear (1739–43) against Spain. Walpole was opposed to the war and resigned in 1742.

In 1743 Britain entered the War of the Austrian Succession as an ally of Austria against France. Much of the fighting between the French and British took place in North America, where the war became known as King George's War. The conflict in Europe and America ended in 1748 with the Treaty of Aix-la-Chapelle. In India, however, fighting between Britain and France over colonial expansion continued for another 15 years.

In 1745 there was a second Jacobite uprising. Scottish Catholic support of Charles Edward Stuart (the “Young Pretender,” or “Bonnie Prince Charlie”) led to the Battle of Culloden in 1746, in which the Jacobites were routed. There were no further efforts to restore the Stuarts to the British throne.

In 1754 the French and Indian War in America renewed Franco-British conflict. Two years later this conflict became part of the Seven Years' War (1756–63), in which France supported Austria, and England allied itself with Prussia. The Treaty of Paris in 1763 ended the war. Britain gained all of French Canada, the French and Spanish holdings east of the Mississippi River, and recognition of its rights to colonial holdings in India. Much of Britain's success in the war was due to the energetic direction of William Pitt (the “Elder Pitt”), who led the government in this critical period.

George III, grandson of George II, came to the throne in 1760. His reign, which lasted until 1820, was one of the most significant in British history. Industrialization, barely begun, now gathered momentum. Also, during this period Britain, which after the Seven Years' War had become dominant on the North American continent, lost all her American colonies south of Canada.

The American Revolutionary War took place during the ministry of Frederick, Lord North (1770–82). The loss of the 13 colonies was somewhat offset by territorial and economic gains elsewhere. British rule in India had been extended by Robert Clive and Warren Hastings. In 1771 Captain James Cook discovered Australia and New Zealand for Great Britain.

With the fall of Lord North's government, there was a struggle for power between William Pitt the Younger and Charles James Fox. It was won by Pitt in 1783. He revived the Tory party and undertook a variety of reforms in government and finance.

When the French Revolution broke out in 1789, British sympathies were at first divided. However, in 1793 the country was drawn into a coalition of European nations at war against France. Gradually, France's enemies were forced out of the war until, in 1797, only Britain and Portugal remained.

Napoleon Bonaparte rose to power in France in 1799, and his colonial ambitions were a challenge to Britain. The victories of Admiral Horatio Nelson led to a temporary peace treaty, the Peace of Amiens, in 1802.

In the meantime the Irish, encouraged by the French, rose against British rule. They were brutally put down. By bribery and promises, Ireland was persuaded to accept an Act of Union. In 1801 the two nations became the United Kingdom of Great Britain and Ireland. A dispute over religious toleration in Ireland developed between Pitt and George III, whose stubbornness was now aggravated by mental imbalance brought on by illness. Pitt resigned.

Napoleon, disregarding the Peace of Amiens, continued his aggressions. In 1803 Britain went to war again. Pitt was recalled to office and formed a new coalition to oppose France. In spite of the British sea victory at Trafalgar (in which Admiral Nelson was killed) in 1805, Napoleon was master of most of Europe by 1806. In the same year, Pitt died.

The next phase of the war was largely economic. Napoleon closed Europe to British trade. In turn, Europe was blockaded by the British navy. In the Peninsular War (1808–13), Spain, Portugal, and Britain opposed Napoleon on the Iberian Peninsula. Sir Arthur Wellesley (later Duke of Wellington), the British commander there, rose to prominence in this campaign.

British interference with United States merchant shipping led to the War of 1812. The war ended in a compromise in 1815.

In 1813 the European nations that had been conquered by Napoleon rose against France. The Napoleonic Wars ended finally with Wellington's victory over Napoleon at Waterloo in 1815. The peace terms worked out at the Congress of Vienna reflected British determination to establish a lasting peace. Under the guidance of Wellington and Lord Castlereagh, the congress created a balance of power that kept Europe at peace for 40 years.

George III was incapacitated after 1809. His son acted as regent and succeeded him in 1820 as George IV. The postwar period had brought desperate financial problems. The Corn Laws, passed by Parliament in 1815 to support the price of grain, made bread a luxury. There was a demand for the reform of electoral laws. The Tory government repressed all expressions of discontent. Ireland, however, was near rebellion because of the continued denial of religious and political rights to Catholics.

Wellington, a Tory, became prime minister in 1828. Laws discriminating against Nonconformists (non-Anglican Protestants) were repealed the same year. The Catholic Emancipation Bill, permitting Roman Catholics to hold all but the highest political offices, was passed in 1829. George IV died in 1830 and was succeeded by his brother, William IV. In the elections, the Tories were defeated.

Under a liberal Whig government the Reform Bill of 1832 was passed. It gave increased parliamentary representation to the cities. Other new laws made local governments more democratic.

The 18th century was a period of developing social conscience. The welfare and freedom of the individual became a matter of concern in Britain as in other countries. Sometimes, however, reform was a long and tedious process.

Britain had engaged early in the transportation of African slaves to the Americas. By the 18th century, however, sentiment among the British people against slavery had become strong. A law halting the British slave trade was enacted in 1807, and slavery was abolished in all British colonies in 1833.

England had brutally harsh penal laws, and efforts began in the early 19th century to revise and modify them. In 1800 more than 200 kinds of offenses could be punished by death. Gradually these were reduced to a handful. Imprisonment for debt was abolished. The game laws prohibiting hunting on estate lands were eased and finally repealed. Beginning in 1836 prisoners were permitted to consult with a lawyer.

Great social changes came to Great Britain in the 18th and 19th centuries as a result of the Industrial Revolution. Improvements in textile machinery, introduction of the steam engine, and advances in transportation (such as construction of canals and paving of roads) caused tremendous industrial growth. The death rate was sharply cut by an increase in medical knowledge and sanitation measures. During the reign of George III (1760–1820), the population almost doubled. People flocked to work in the coal mines, the textile mills, and the ironworks. New towns grew up around the booming industries.

The living standard of the working people was distressingly low, however, and working conditions were deplorable. A demand for reform slowly developed. The Factory Act of 1833 limited the working hours of young persons and specified certain improvements in overall working conditions. In 1834 the Poor Law was revised to require factory owners to pay higher wages.