Married a German princess, Charlotte of Mecklenburg on 8th September 1761. The coronation was delayed until after wedding, so that the couple could both be crowned. This took place in Westminster Abbey on 22 September 1761.
  
George III has been popularly remembered for having been devoted to his wife. The couple had 15 children.

The reign of George III saw the British empire reach its widest ranging point. The Seven Years War (1756-1763), a conflict that had raged around the world, saw massive British gains in India, North America and across the globe. After the Seven Years War, Britain was clearly the dominant colonial power in the world, particularly after the successes of the Napoleonic wars later in the period. At its height, the British empire covered almost one third of the globe. 

Britain survived both the French Revolution and the Napoleonic wars. The French Revolution, which began in 1789, caused many other revolutions throughout Europe as long-existing regimes were toppled. The British system survived. Napoleon'a armies carried all before them right up to the Russian heartlands, but the British held out.

This was due in no small part to the powerful navy that had emerged from the Seven Years War with such credit. Nelson, whose statue stands in Trafalgar Square in London, won several important naval battles. The scene of his greatest victory was also the scene of his death at the battle of Trafalgar in October 1805.

On the battlefield, the British were indebted to Arthur Wellesley, who became The Duke of Wellington. It was Wellington who inflicted Napoleon's final defeat, at the battle of Waterloo, in 1815.
 
The population drastically increased during the period, which pointed to better living conditions. This growth led to improvements in industry and agriculture so that food and clothing could be provided. There were also changes in transport. Roads were improved and the canal system was developed. 

It was also a period of relative reform. In 1807, the slave trade was abolished in lands under British control, although it did not die out completely until 1833. 

When George III came to the throne, the ruling political party was the Whigs. The other political party at the time were the Tories. The Whigs had been in power since the Hanoverian dynasty had begun. With the reigns of George I and George II, Whig ministers had become more and more powerful. Men such as Sir Robert Walpole (considered to be the first Prime Minister) and the Duke of Newcastle were able to dominate politics for long periods of time.  

When George III came to the throne it was at the height of this ministerial power. The Prime Minister at the time was William Pitt (the elder) and he was guiding Britain to success in the Seven Years War. George III was determined to break up the power of the government and reassert the power of the monarchy. He attempted to do this by playing the politicians at their own game and using his own patronage system, giving important positions to men in return for their loyalty. 

Soon after he began his reign, he appointed his own favourite, Bute, as the chief minister. However, due to his failings as a minister and the resentment at his appointement, Bute was forced to resign. There followed a series of governments who all failed in their attempts to stabilise power, before the king installed someone who was able to hold power for a reasonable period of time. This was Lord North, who was Prime Minister from 1770 to 1782.

These problems weakened the position of the king. It was now clear that the position of a king or queen in Britain was no longer as powerful as it had once been. For government to work effectively, there had to be a balance between the Monarch, the House of Lords and the House of Commons. George III was trying to weight that balance in his favour but the events of the 1760s showed that the king could no longer act alone.

Perhaps the lowest point in the reign of George III was the loss of the American colonies after the War of American Independence. The Americans had been angered by the fact that the British had made them pay certain taxes. The final straw was the tax placed on tea. When the British ships arrived in Boston harbour with their delivery, the Americans pushed all the tea into the sea. This is known as the Boston Tea Party. This led to war. The Americans signed and published the Declaration of Independence on July 4th 1776 and defeated the British in a series of battles before peace was declared in 1783. The loss of the American colonies led to a crisis at home and was a major factor in the fall of Lord North's government.

There were also difficulties caused by the French Revolution. Many were inspired by some of the ideas of the French revolutionaries but others, such as Edmund Burke, regarded such ideas as dangerous. There were a series of wars fought with the French and in particular with Napoleon Bonaparte; these did not end until 1815. The wars cost many lives and millions of pounds.

George III also suffered from a disease which people at the time took to be madness. The film The Madness of King George refers to George III. Doctors have now been able to diagnose the disease as porphyria. The disease often hindered George III in his attempts to rule and indeed from 1811, until his death in 1820, his son Prince George (later George IV) took over many of his responsibilities. In that period he was referred to as the Prince Regent.

King George III was the first of the Hanoverians to be born in England. Both his grandfather and great-grandfather had been born and raised in Hanover, which was a duchy in Germany.

Among the significant introductions during the reign of George III was income tax, which was introduced by William Pitt (the Younger). The tax was only supposed to be introduced for the war with France, but it remains in place today.
    
Spencer Perceval became the only British Prime Minister ever to be assassinated when he was shot in the lobby of the House of Commons by John Bellingham on 11 May 1812. Bellingham was executed a week later.    

This was a period of famous figures. Great political names like William Pitt the Elder, William Pitt the Younger, and Charles James Fox made their names in this period. There were also great figures in English literature such as Jane Austen, William Wordsworth, and the poets Lord Byron, Shelley and Keats. Dr Johnson wrote the first dictionary. In addition, the Royal Academy was founded, with its first president, Reynolds, a notable artist.

I can never suppose this country so far lost to all ideas of self-importance as to be willing to grant America independence; if that could never be adopted I shall despair of this country being ever preserved from a state of inferiority and consequently falling into a very low class among the European States.

George III wrote this in a letter to his Prime Minister Lord North on March 7th, 1780 concerning his worries over losing the American colonies.