The Royal Proclamation of 1763 was issued by King George III on 7 October 1763. It followed the Treaty of Paris (1763), which formally ended the Seven Years' War and transferred French territory in North America to Great Britain. The Proclamation forbade all settlements west of a line drawn along the Appalachian Mountains, which was delineated as an Indian Reserve. Exclusion from the vast region of Trans-Appalachia created discontent between Britain and colonial land speculators and potential settlers. The proclamation and access to western lands was one of the first significant areas of dispute between Britain and the colonies and would become a contributing factor leading to the American Revolution. The 1763 proclamation line is more or less similar to the Eastern Continental Divide, extending from Georgia in the south to the divide's northern terminus near the middle of the northern border of Pennsylvania, where it intersects the northeasterly St. Lawrence Divide, and extends further through New England.

George III was King of Great Britain and Ireland from 25 October 1760 until his death in 1820. The Acts of Union 1800 unified Great Britain and Ireland into the United Kingdom of Great Britain and Ireland, with George as its king. He was concurrently Duke and Prince-elector of Hanover in the Holy Roman Empire before becoming King of Hanover on 12 October 1814. He was a monarch of the House of Hanover, who, unlike his two predecessors, was born in Great Britain, spoke English as his first language, and never visited Hanover.