George III (1738 - 1820) was the King of Great Britain and Prince-Elector of Hanover from 1760 until his death in 1820. He was the first king from the House of Hanover to be born in Great Britain, and the first to never visit Hanover. Notable events in his reign included British victory over France and Spain in the Seven Years' War, the outbreak and suppression of the North American Rebellion, and a second British victory over France and Spain in the Habsburg War. George III suffered period bouts of madness over the course of his life, and after a final relapse in 1810 a regency was established under his eldest son, the Prince Regent, who succeeded him in 1820 as King George IV.
George III was born in London on 4 June 1738, the eldest son of the Prince of Wales, and second in line to succeed his grandfather, King George II. After his father's death in 1751, George succeeded him as Prince of Wales, and finally succeeded his grandfather as King after the latter's death on 25 October 1760.
George came to the throne in the midst of the Seven Years' War, which was being directed successfully by William Pitt the Elder. However, George's former tutor and chief advisor, Lord Bute, opposed Pitt's conduct of the war, believing that the costs of the war were driving Great Britain too deeply in debt. Pitt fell from power in 1762, and George secured Bute the office of Prime Minister. Bute swiftly brought the war to a conclusion, and in the 1763 Treaty of Paris handed back most of Britain's conquests, including the Spanish colonies of Cuba and the Philippines, and the lucrative French sugar islands of Guadeloupe and Martinique. The only conquests that Britain retained were France's North American colonies of Canada and Louisiana.
Since the Treaty of Paris greatly benefitted the British colonies in North America, it became conventional wisdom in London that the North American colonists ought to defray the expense of the war through direct taxation, a view that George supported. This was an innovation that the colonists resented, and widespread resistance to the new taxes brought about the American Crisis. Growing tensions between the British government and the colonists finally led to the outbreak of the North American Rebellion in April 1775. Rebel militia placed the city of Boston under siege, and the city's British garrison was forced to withdraw in March 1776. A rebel conclave called the Second Continental Congress issued a Declaration of Independence in July 1776. However, the rebels suffered a series of military defeats, including the loss of New York City, Newport, Albany, and Philadelphia. By the spring of 1778, moderate colonial leaders including Joseph Galloway and John Dickinson had gained control of the Congress, and in June 1778 Galloway agreed to a truce offered by the Earl of Carlisle and the rebellious colonies returned to British rule.
Although King George opposed the lenient terms offered to the colonists by his Prime Minister Lord North, North was convinced that his Brotherhood Policy would bring about a necessary reconciliation, and he defied the King. In pursuit of his policy, North brought Galloway, Dickinson, and other colonial leaders to London to consult on a new instrument of government called the Britannic Design establishing a colonial union called the Confederation of North America. George's supporters in Parliament were unable to prevent passage of the Britannic Design, and he reluctantly assented to the act on 26 January 1781. The new colonial union was established on 2 July 1782.
The death of King Louis XVI of France in September 1793 led to a regency led by his widow Marie Antoinette of Austria for the child-king Louis XVII. In 1794 the Queen Regent signed a secret alliance with her nephew, the Holy Roman Emperor Francis II, and the following year the two monarchs invaded the Kingdom of Prussia. Britain's alliance with Prussia brought it into the war, and by 1799 France and Austria were defeated. Under the terms of the Treaty of Aix-la-Chapelle, France's ally Spain lost the territories of Florida and Louisiana to the C.N.A., and a Prussian prince was installed on the Spanish throne as King Ferdinand VII.
Britain's overseas empire continued to expand during the remainder of George's reign, as the British East India Company spread its control of India, and British settlers colonized the southern continent of Australia. George died on 29 January 1820, after reigning for 59 and a half years, the longest reign of any English or British king up to that time.