Jacob Johan Anckarström (11 May 1762 – 27 April 1792) was a Swedish military officer who is known as the assassin of King Gustav III of Sweden. He was convicted and executed for regicide. Life. He was the son of Jacob Johan Anckarström the Elder and Hedvig Ulrika Drufva. He married Gustaviana Elisabet Löwen (1764-1844) in 1783, and had two daughters and two sons: Gustafva Eleonora Löwenström (1785-1860), Carolina Lovisa, Johan Jacob and Carl David. Anckarström served as a page at court and then as a captain in King Gustav III's regiment between 1778 and 1783.
https://en.wikipedia.org/wiki/Jacob_Johan_Anckarstr%C3%B6m