Witt, Jan de (yän) [key], 1625–72, Dutch statesman. Like his father, Jacob de Witt, burgomaster of Dort, he became a leading opponent of the house of Orange and played a vital role in the three successive Dutch Wars. As leader of the republican party, he was elected (1653) grand pensionary, thus acquiring control of state affairs. He represented the mercantile interests and accordingly encouraged industry and commerce. He ended the disastrous war with England (first of the Dutch Wars) in 1654, but the Restoration in England was considered a danger to Dutch maritime and political freedom and led to the renewal of the war in 1665. The favorable (to the Dutch) terms of the Treaty of Breda (1667) were largely due to Jan de Witt. In order to end the power of the house of Orange he secured passage of the Eternal Edict, which abolished the office of stadt-holder. He helped form the Triple Alliance of 1668 against Louis XIV, thus ending the War of Devolution; the Treaty of Aix-la-Chapelle (1668) was the climax of his career. In 1672, Louis XIV invaded Holland and began the third of the Dutch Wars. Jan de Witt sought to negotiate peace, but his offer was spurned by the French. Popular feeling suddenly turned violently against him and in favor of William of Orange (later William III of England), who by popular acclaim was made stadtholder. De Witt resigned, but was exonerated of treason charges. However, when he visited his brother, Cornelius de Witt, in prison, a mob gathered outside, fought its way into the prison, and hacked the two brothers to pieces, hanging their scattered limbs on lamp posts. De Witt was one of the greatest of Dutch statesmen and patriots, a patron of the sciences, and a close friend of Spinoza.
See H. H. Rowen, Jan de Witt (1986).