Who married Charles William Ferdinand, Duke of Brunswick?

Charles William Ferdinand (German: Karl Wilhelm Ferdinand; 9 October 1735 – 10 November 1806) was the ruling prince of Brunswick-Wolfenbüttel, hereditary duke of Brunswick-Lüneburg and a military leader. His titles are usually shortened to Duke of Brunswick in English-language sources.

He succeeded his father as sovereign prince of the Principality of Brunswick-Wolfenbüttel, one of the princely states of the Holy Roman Empire. The duke was a cultured and benevolent despot in the model of his uncle, Frederick the Great, and was married to Princess Augusta, the eldest sister of George III of Great Britain. He was also a recognized master of 18th century warfare, serving as a field marshal in the Prussian Army. He played a notable role in the French Revolutionary Wars by issuing the Brunswick Manifesto. During the Napoleonic Wars, he was mortally wounded by a musket ball at the Battle of Jena–Auerstedt in 1806.

Augusta of Great Britain (Augusta Frederica; 31 July 1737 – 23 March 1813) was a British princess, granddaughter of George II and the only elder sibling of George III. She was Duchess of Brunswick-Lüneburg and Princess of Brunswick-Wolfenbüttel by marriage to Charles William Ferdinand, Duke of Brunswick. Her daughter Caroline was the wife of George IV.