November 2, 1755 - October 16, 1793: Age 38
Marie Antoinette was born as an Archduchess of Austria. Her mother, the Empress of the Holy Roman Empire and Queen of Hungary, was a formidable woman who read and signed state papers while in labour with Marie Antoinette, who was her 15th child.
The main job of a young royal female in those days was to get married as advantageously as possible, but since Antoinette had 10 sisters she didn't receive much attention until 1767, when a smallpox epidemic reduced the number of eligible sisters by two. Other sisters were already married (except one who was crippled and ineligible) so plans began for a marriage between the young Antoinette and the Dauphin of France. She was married by proxy in April 1770 (age 14) and was handed over to the French in May. She became Queen four years later, when her father-in-law died of smallpox.
Then came the French Revolution. 1989, with the storming of the Bastille, marked the end of any real royal power in France. Popular hatred for the aristocracy gradually and inevitably extended to hatred for the King and Queen, and by 1792 their legal power was abolished and they became known as "Louis and Antoinette Capet" and imprisoned. In December of that year Louis was put to trial for "undermining the Repulic" and condemned to death, which followed by guillotine in January. Antoinette, became known as "Veuve Capet" (Widow Capet). Imprisoned with her surviving son and daughter (two children had died in infancy), she fell into a deep depression.
Her 8-year-old son, Louis Charles, by rights the King of France, was taken away from her in July and given into the "care" of a cobbler. There he was mistreated and coached to hate his parents. In October Antoinette was put on trial for various crimes for which there was not a shred of real evidence, including the allegation that she had sexually abused and masturbated her son. The boy was brought into court and coached into accusing his mother, causing her great distress. The conclusion was pre-ordained: she was found guilty on all counts.
Early on the morning of her execution her hair was cut and her hands bound. She was put in a open cart and carried through the streets of Paris to the Place de la Révolution. When she stepped down from the cart and looked up at the guillotine, the priest whispered, "This is the moment, Madame, to arm yourself with courage." She replied, "Courage? The moment when my troubles are going to end is not the moment when my courage is going to fail me."
When she mounted the platform she accidentally stepped on the executioner's foot, and said, "Monsieur, I ask your pardon. I did not do it on purpose." These were her last words. She was executed shortly after noon. Her head was displayed to a cheering crowd; and her body was dumped in an unmarked mass grave in the Rue d'Anjou. (In 1815 it was retrieved and reburied at St. Denis Cathedral.)
Sources: The Free Republic, Wikipedia