Adolph Ludvig Ribbing, later called Adolph de Leuven (10 January 1765 in Stockholm – 1 April 1843 in Paris), was a Swedish count and politician. He participated in the regicide of Gustav III of Sweden in 1792. Life Early life Adolph Ribbing was the son of Count Fredrik Ribbing and Eva Helena Löwen. He spent his childhood at the Swedish royal court, as his mother was a popular socialite and the personal friend of both Louisa Ulrika of Prussia and Gustav III of Sweden. He received a military education in Berlin and Paris and became a member of the Life Guards. Assassination of Gustav III In the 1780s, Ribbing came in conflict with the monarch, Gustav III. His animosity was nurtured when Charlotta Eleonora De Geer, with whom he was in love, was matched by the king with count Hans Henrik von Essen. The engagement was widely disapproved of within the court because of sympathy with the popular Augusta von Fersen, to whom von Essen had been a long term lover, and Ribbing challenged von Essen to a duel. Ribbing injured von Essen in the duel, which took place in 1788. The duel caused a scandal and was regarded as a crime against the king. Ribbing was assigned to the garrison at Vaxholm Castle, which he regarded as an insult, and he therefore resigned from the army. Ribbing took part in the of the Riksdag (the Swedish parliament), acting as one of the leaders of the opposition to the king's increasingly autocratic policies, such as the Union and Security Act. In early 1792 he became involved in the plot to assassinate King Gustav, serving as the liaison between the conspiracy's leader Carl Fredrik Pechlin and the two men who had volunteered to carry out the murder, and Jacob Johan Anckarström in 1792. When Anckarström, Horn and Ribbing met on the afternoon of 16 March to finalise their plans, they did so at the house of Ribbing's lover, Louisa Hierta. That evening, the three conspirators attended a masquerade ball at the Royal Opera House, during which either Anckarström or Ribbing (who boasted of it later when in exile) shot and wounded the king. Ribbing was arrested within a few days of the assassination and confessed to partaking in the conspiracy. Ribbing was sentenced to death in May 1792 and deprived of his rank as a noble, but the regent Duke Charles