A right-facing laureated and draped bust of King George III right, surrounded by the legend in Latin "George the Third by the Grace of God".

George III (George William Frederick; 1738–1820) was King of Great Britain and Ireland from 25 October 1760 until the union of the two countries on 1 January 1801, after which he was King of the United Kingdom of Great Britain and Ireland until his death.

His life and reign, which were longer than any other British monarch before him, were marked by a series of military conflicts involving his kingdoms, much of the rest of Europe, and places farther afield in Africa, the Americas and Asia. 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 Revolutionary War. Further wars against revolutionary and Napoleonic France from 1793 concluded in the defeat of Napoleon at the Battle of Waterloo in 1815.

In the later part of his life, George III had recurrent, and eventually permanent, mental illness. Although it has since been suggested that he had the blood disease porphyria, the cause of his illness remains unknown. After a final relapse in 1810, a regency was established, and George III's eldest son, George, Prince of Wales, ruled as Prince Regent.

Cruciform shields of Electorate of Hanover (coat of arms of Brunswick, Luneburg, Hanover, Arch-Treasurer of the Holy Roman Empire), England and Scotland (arms are impaled), France and Ireland, around central Garter star with crowns in angles, legend around, date below.

Legend: King of Great Britain, France and Ireland, Defender of the Faith, Duke of Brunswick and Lueneburg, Arch Treasurer and Elector of the Holy Roman Empire

The Order of the Garter (formally the Most Noble Order of the Garter) is an order of chivalry founded by Edward III in 1348 and regarded as the most prestigious British order of chivalry in England and the United Kingdom. The star, which is worn pinned to the left breast, was introduced in the 17th century by King Charles I and is a colourfully enamelled depiction of the heraldic shield of St. George's Cross, encircled by the Garter, which is itself encircled by an eight-point silver badge. Each point is depicted as a cluster of rays, with the four points of the cardinal directions longer than the intermediate ones.