Napoleon Bonaparte, aged 23 —
Photo Credit: By Henri Félix Emmanuel Philippoteaux - Transferred from de.wikipedia to Commons by Stefan Bernd.Alt source: [1], Public Domain, https://commons.wikimedia.org/w/index.php?curid=5556134

Marie Antoinette's execution — on 16 October 1793: Sanson, the executioner, showing Marie Antoinette's head to the people (anonymous, 1793).
Photo Credit: By Unknown - http://www.artres.com/Doc/ART/Media/TR3/F/M/8/Q/ART1662.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1056466

Storming of the Bastille — and arrest of Governor Bernard-René de Launay, 14 July 1789
Photo Credit: By Anonymous - L’Histoire par l’image, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6882732

Marriage of Marie Antoinette with Louis-Auguste — Celebrated in the Royal Chapel of Versailles by the Archbishop-Duke of Reims on May 16, 1770
Photo Credit: By Claude-Louis Desrais (1746-1816) - RMN[1], Public Domain, https://commons.wikimedia.org/w/index.php?curid=4427067

Marie Antoinette at the age of 13 — Portrait sent to the Dauphin to show him what his future bride looked like (by Joseph Ducreux, 1769)
Photo Credit: By Joseph Ducreux - http://www.ladyreading.net/marieantoinette/index-en.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=5012606

Marie Antoinette in hunting attire — One of her mother's favorite portraits of her daughter (by Joseph Krantzinger, 1771)
Photo Credit: By Joseph Kreutzinger - http://www.ladyreading.net/marieantoinette/big/marie19.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1021725

Marie Antoinette —
Photo Credit: By Joseph Kreutzinger - http://www.ladyreading.net/marieantoinette/big/marie19.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1021725

Execution of Louis XVI — In the Place de la Révolution. The empty pedestal in front of him had supported an equestrian statue of his grandfather, Louis XV. When the monarchy was abolished on 21 September 1792, the statue was torn down and sent to be melted.
Photo Credit: By Isidore Stanislas Helman - Bibliothèque nationale de France, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17446087

Louis XVI imprisoned at the Tour du Temple —
Photo Credit: By Jean-François Garneray - Own work PHGCOM, 2009, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6410768

Louis XVI at the age of 20 —
Photo Credit: By Joseph Duplessis - Unknown, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1302669

Nero — cropped
Photo Credit: By cjh1452000 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6983878