Johan Kievit (1627–1692) was an Orangist Rotterdam Regent, who may have been one of the instigators of the murder of former Grand Pensionary Johan de Witt, of the Dutch Republic, and his brother Cornelis de Witt on 20 August 1672, together with his brother-in-law, Cornelis Tromp. Biography Early life Johan Kievit (first name sometimes spelled Joan or Johannes; last name variously given as Kievidt or Kiewit) was the son of Nicolaas Kievit and Dieuwertje Pauw, both of well-known Rotterdam families. He married Alida Tromp, the daughter of lieutenant-admiral Maarten Tromp on 27 April 1653 when she was only 16 (and he 26). He practiced law before the Hof van Holland (the main law court of the province of Holland), before going into politics in 1659, when he became a member of the Rotterdam vroedschap. In May 1666 he was appointed a member of the Gecommitteerde Raden (Committed Councillors - the Executive) of the States of Holland and West Friesland. The Buat-conspiracy Kievit was a partisan of the young Prince of Orange, William III, who had been excluded from high office by the States-Party regent faction of Johan de Witt during the First Stadtholderless Period. As such he became involved in the treasonous correspondence of Henri de Fleury de Coulan, lord of Buat, better known as "cavalry-captain Buat," with the English court of William's uncle Charles II of England, during the Second Anglo-Dutch War. Buat was executed for treason, but Kievit managed to escape to England. He was sentenced to death for his part in the conspiracy in absentia. In England he became a favorite of Charles who made him a baronet. Even before the conspiracy was discovered, Kievit was fired from his position in the gecommitteerde raden, because he published a libelous pamphlet, entitled Brief van den heer van Sommelsdijk ("Letter of Lord Sommelsdijk"), in which he defended his brother-in-law lieutenant-admiral Cornelis Tromp's conduct during the St. James's Day Battle, disparaging lieutenant-admiral Michiel de Ruyter at the same time. The murder of the De Witt brothers When the Dutch Republic was attacked by France, England, and two German principalities in 1672, Kievit's political fortunes changed again. The attack caused a severe political crisis in the Dutch Republic during this Rampjaar ("Year of disaster"). Because of the military disaster the De Witt regime was forced to retract the Perpetual Edict (1667) and to appoint Prince William first Captain general (in January),