Cause of death: apoplexy
Nicolas Fouquet, marquis de Belle-Île, vicomte de Melun et Vaux (French pronunciation: [nikɔla fukɛ]; 27 January 1615 – 23 March 1680) was the Superintendent of Finances in France from 1653 until 1661 under King Louis XIV. He had a glittering career, and acquired enormous wealth. He fell out of favor, accused of peculation (maladministration of the state's funds) and lèse-majesté (disrespect to the monarch). The king had him imprisoned from 1661 until his death in 1680.
Source : Wikipedia