He served as Intendant of Lyon (1768–1784) and in 1784 he was sponsor of a Montgolfier balloon, named the Flesselles in his honour.
Engraving, c.1789: French soldiers or militia hoisting the heads of Flesselles and the marquis de Launay on pikes. The caption reads "Thus we avenge the traitors".
On 21 April 1789, he became the last provost of the merchants of Paris, a post roughly equivalent to mayor. Accused of royal sympathies by an infuriated throng surrounding the Paris City Hall in the afternoon after the storming of the Bastille, he was assassinated, shot by an unknown hand on the steps of the City Hall while trying to justify his actions, one of several representatives of the ancien régime killed that day.
^Charles Coulston Gillispie - Science and Polity in France: The End of the Old Regime p23 2004 "To that end they persuaded Jacques de Flesselles to preside. Prévôt des Marchands since the previous April, ... of a manned Montgolfier balloon outside of Paris."