George III was the third British monarch of the House of Hanover, but unlike his two predecessors, he was born in Great Britain, spoke English as his first language, and never visited Hanover. His reign was marked by a series of military conflicts involving his kingdoms, much of the rest of Europe, and places farther afield. Early in his reign, Great Britain defeated France in the Seven Years' War, becoming the dominant European power in North America and India. However, many of Britain's American colonies were soon lost in the American War of Independence. Further wars against revolutionary and Napoleonic France from 1793 concluded in the defeat of Napoleon at the Battle of Waterloo in 1815.

Later in life, George III had recurrent mental illness. After a final relapse in 1810, a regency was established, and George III's eldest son, George, Prince of Wales, ruled as Prince Regent.

The Napoleonic Wars were a series of major conflicts pitting the French Empire and its allies, led by Napoleon I, against a fluctuating array of European powers formed into various coalitions, financed and usually led by the United Kingdom. The wars stemmed from the unresolved disputes associated with the French Revolution and its resultant conflict

Spencer Perceval (1 November 1762 – 11 May 1812) was a British statesman who served as Prime Minister of the United Kingdom from October 1809 until his assassination in May 1812.[1] Perceval is the only British prime minister to have been murdered. He was also the only Solicitor General or Attorney General to become Prime Minister.

Perceval faced a number of crises during his term in office, including an inquiry into the Walcheren expedition, the madness of King George III, economic depression and Luddite riots. He overcame these crises, successfully pursued the Peninsular War in the face of opposition defeatism, and won the support of the Prince Regent. His position was looking stronger by early 1812, when, in the lobby of the House of Commons, he was assassinated by a merchant with a grievance against his government.