Jean-Sylvain Bailly (September 15, 1736 - November 12, 1793) was a French astronomer, mathematician, and political leader of the early part of the French Revolution. He calculated an orbit for the next appearance of Halley's Comet (in 1759), and correctly reduced Lacaille's observations of 515 stars. He was elected to the 31st seat of the French Academy of Sciences in 1763. He devoted himself to the history of science, publishing A History of Ancient Astronomy in 1775, followed by A History of Modern Astronomy in 1782. After the storming of the Bastille (1789) he became the first mayor of Paris. When Louis XVI endorsed the Revolution, Bailly presented him with the new symbol of the revolution, the tricolor cockade. In 1791 he pushed for the passage of a decree which declared Jews to be French citizens, with all rights and privileges. This decree repealed the special taxes that had been imposed on the Jews, as well as all the ordinances existing against them. The dispersal by the National Guard, under his orders, of the riotous assembly in the Champ de Mars made him extremely unpopular, and he retired to Nantes. In 1793 he was asked to testify against Marie Antoinette, but he refused. He was brought before the Revolutionary Tribunal at Paris, speedily tried, and sentenced to death the next day by guillotine. He was forced to endure the freezing rain and the insults of a howling mob. He was 57 years old.