Gustav III was King of Sweden from 1771 until his assassination in 1792. He was the eldest son of King Adolf Frederick of Sweden and Queen Louise Ulrika (a sister of King Frederick the Great of Prussia), and a first cousin of Empress Catherine the Great of Russia by reason of their common descent from Christian August of Holstein-Gottorp, Prince of Eutin, and his wife Albertina Frederica of Baden-Durlach.
Following the French Revolution of 1789, Gustav pursued an alliance of monarchs aimed at crushing the insurrection and re-instating his French counterpart, King Louis XVI, by offering Swedish assistance to the royal cause in France under his leadership. He was mortally wounded by a gunshot in the lower back during a masquerade ball as part of an aristocratic-parliamentary coup attempt, but managed to assume command and quell the uprising before succumbing to septicemia 13 days later, a period during which he received apologies from many of his political enemies. Gustav's immense powers were placed in the hands of a regency under his brother Prince Carl until his son and successor Gustav IV Adolf reached adulthood in 1796. The Gustavian autocracy hence survived until 1809, when his son abdicated the Swedish throne.