Jacob Johan Anckarström (11 May 1762 – 27 April 1792) was a Swedish military officer who assassinated Gustav III, king of Sweden. He was convicted and executed for regicide.
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. During travels to Gotland, he was accused of slandering the king and fled to Stockholm, where he spent the winter; he was subsequently arrested, brought back, and tried in Gotland. Although he was acquitted due to lack of evidence, he later maintained in his confession that this incident sparked his fire of hatred towards the king, fuelled by the contemporary revolutionary movement in Europe.
The Swedish nobles were about this time violently opposed to the king, who, by the aid of the other orders of the state, had wrested their power from them and was now ruling despotically. This dislike was increased by the coup d'état of 1789 and by the king's known desire to interfere in favor of Louis XVIII in France. Anckarström, a man of strong passions and violent temper, resolved upon the assassination of Gustav and communicated his intention to other disaffected nobles, including Counts Horn and Ribbing.
Initial attempts to seize the king were failures.
On 16 March 1792, Gustav III had returned to Stockholm, after spending the day at Haga Palace outside the city, to dine and visit a masquerade ball at the Royal Opera. During dinner, he received an anonymous letter (written by the colonel of the Life Guards, Carl Pontus Lilliehorn) that contained a threat to his life, but as the king had received numerous threatening letters in the past, he chose to ignore the warning.
After dining, he left his rooms to take part in the masquerade. Soon after entering, he was surrounded by Anckarström and his conspirators, including Horn and Ribbing, who wore black masks. When Horn confirmed that it was the king, he greeted him in French with the words "Bonjour, beau masque" ("Hello, lovely mask."). Anckarström then moved in behind the king and fired a pistol into the left side of his back. The murder weapon was loaded with two balls, five shot and six bent nails. The King jumped aside, crying in French "Ah! Je suis blessé, tirez-moi d'ici et arrêtez-le!" ("Ah! I am wounded, take me away from here and stop him!"). The king was immediately carried back to his quarters, and the exits of the Opera were sealed. Anckarström was able to flee before the doors were sealed but had thrown the pistol down as he left. These were brought around to several gunsmiths the next morning and one who had repaired them for Anckarström recognized them and identified him as their owner. Anckarström was arrested the same morning and immediately confessed to the murder, although he denied a conspiracy until he was informed that Horn and Ribbing had been arrested and confessed in full.
Anckarström was jailed in a prison not far from the Royal Palace in Stockholm. Today the former prison is an underground restaurant named after the viceroy Sten Sture.
Curiously, the murder had been predicted to the king four years earlier, when he paid an anonymous visit to the celebrated medium of the Gustavian era, Ulrica Arfvidsson. She was often employed by his brother, Duke Charles, and was said to have a large net of informers all over town; she was never suspected to be involved, but she was questioned about the murder. In 1791, Charlotta Roos also predicted misfortune to King Gustav III, something he reportedly referred to on his death bed after the assassination.
Gustav III died of his wounds on 29 March and on 16 April Anckarström was sentenced. He was stripped of his estates and nobility privileges. He was sentenced to be cast in irons for three days and publicly flogged, his right hand to be cut off, his head removed, and his corpse quartered. The execution took place on 27 April 1792. He endured his sufferings with the greatest fortitude, and seemed to rejoice in having rid his country of a tyrant. His principal accomplices were imprisoned for life.
In the same year, the Anckarström family changed its surname to Löwenström and donated funds for a hospital as a gift of appeasement. This resulted in the Löwenström Hospital, or Löwenströmska lasarettet in Upplands Väsby north of Stockholm. Living descendants of Anckarström include Ulf Adelsohn and the American actress Alexandra Neil.
Anckarström is a character in Daniel Auber's opera Gustave III and Giuseppe Verdi's Un ballo in maschera (A Masked Ball). In the operas, his motivation is changed to jealousy over his wife Amelia, with whom Gustav is portrayed as being in love. He is actually portrayed as being Gustav's close friend before he switches allegiances. Gustav pardons him with his last breath. In the censored version of the Verdi libretto, set in Colonial-era Boston, he is called Renato (Rene).