Execution of Marie Antoinette
Held in the Conciergerie, the queen was condemned for treason by the Revolutionary Tribunal and guillotined the next day.

Jacques-Louis David · Public domain · Source
After Louis XVI’s execution Marie Antoinette was separated from her son and moved to the Conciergerie prison in August 1793. At her trial before the Revolutionary Tribunal, which opened on 14 October, she was accused of conspiring with foreign powers and squandering the nation’s wealth, and even monstrous charges concerning her son were raised. She was condemned in the early hours of 16 October.
That day she was driven in an open cart, hands bound, to the Place de la Révolution and guillotined. David, watching from the roadside, sketched her final appearance. There is no evidence that she ever said “Let them eat cake”.