King George III reigned from October 25 1760 to January 29, 1820, the entirety of Austen's life (1775-1817). During this time, he was married to Queen Charlotte of Mecklenburg-Strelitz with whom he had 15 children: George IV (future king of England) (1762), Frederick (1763), William IV (future king of England) (1765), Charlotte (1766), Edward (1767), Augusta Sophia (1768), Elizabeth (1770), Ernest Augustus (1771), Augustus Frederick (1773), Adolphus (1774), Mary (1776), Sophia (1777), Octavius (1779), Alfred (1780), and Amelia (1783). During his reign, America gained independence from England through the American War of Independence, the French had their French Revolution followed by the defeat of Napoleon, and the transatlantic slave trade was banned in England (1807).

“George III.” Wikipedia, Wikimedia Foundation, 19 Sept. 2022, https://en.wikipedia.org/wiki/George_III.