On 12 November 1793, a day of wet, numbing cold, a grim and unique ceremony took place on the Champ de Mars, the open space in south-western Paris where the Festival of Federation had been celebrated in 1790, and where today stands the Eiffel Tower. In 1793, for that one day alone, the centre of this vast space was occupied by the guillotine. A single victim journeyed there in the executioner's cart from prison in central Paris, reviled along the route by screaming crowds that twice attempted to break through the cordon of guards and seize him. Jean-Sylvain Bailly, astronomer, academician, doyen of the Third Estate in the Estates-General of 1789 and mayor of Paris from July of that year until November 1791, perished on that dank day for the crimes that the Republic laid against him, crimes that occurred in the summer of 1791.

Bailly was accused of orchestrating, with Queen Marie-Antoinette, executed a scant four weeks earlier, the attempted escape of the royal family in the ‘Flight to Varennes’ of 21 June 1791. Further, and decisively, he was charged with plotting the massacre of ‘patriots’ which ensued on 17 July 1791, as they attempted to meet on the Champ de Mars to protest against the National Assembly's decision to reinstate the recaptured monarch. Hence the site of his execution. The tribunal's verdict on his guilt had noted that Bailly had ‘thirst[ed] for the blood of the people’.