Prince Octavius of Great Britain was the thirteenth child and eighth son of King George III and his queen consort, Charlotte of Mecklenburg-Strelitz. Six months after the death of his younger brother Prince Alfred, Octavius was inoculated against the smallpox virus. Several days later, he became ill. His subsequent death at the age of four devastated his parents, and in particular his father. King George III had been very fond of his two youngest sons, Alfred and Octavius, and his later bouts of madness involved hallucinations of them.

Charlotte of Mecklenburg-Strelitz was Queen of Great Britain and Ireland as the wife of King George III from their marriage on 8 September 1761 until her death in 1818. The Acts of Union 1800 unified Great Britain and Ireland into the United Kingdom of Great Britain and Ireland. As George's wife, she was also Electress of Hanover until becoming Queen of Hanover on 12 October 1814. Charlotte was Britain's longest-serving queen consort, serving for 57 years and 70 days.