George II of Britain and Hanover dies, and, because his eldest son Frederick had died in 1751, he is succeeded by his grandson George III, aged 22. George III is to reign until 1820, but from 1788 onwards he suffers episodes of mental illness (probably porphyria), and after 1810 a regency is established, with his son George IV effectively ruling in his stead.
Editors. "Reign of King George III". The Literary Encyclopedia. First published 01 March 2011; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=628, accessed 28 April 2015.]