January 25, 1477 – January 9, 1514: Age 36
Anne de Bretagne was the only surviving daughter of the Duke of Brittany, at that time an independent kingdom, constantly threatened by the imperialist schemes of France. Although the legality of a woman inheriting the title was murky at best, her father recognized her as the official heir when she was nine. And not a moment too soon: he died two years later after a fall from his horse. In late 1490, when she was 13, she was married by proxy to Maximilan of Hapsburg, King of the Romans. The King of France, however, didn't take kindly to the ruler of Brittany marrying an enemy of France, and forced the Pope to annul the marriage so that he could marry Anne himself.
The marriage began badly, with Anne pointedly arriving at her new home with two beds. She was just turning 15. She became pregnant seven times by the King, but only four of the babies were born alive, and three of them died in infancy. Their son, Charles, survived longer than the others; but he died of measles at the age of three.
The King himself died in 1498, leaving Anne a widow at 21. Although there was an agreement that, should the King die before her, she would marry his heir, said heir was already married. Anne agreed that she would marry him provided he had his current marriage annulled, and returned to Brittany to rule as Duchess. It may be that she didn't think he would do it, but he did, and once again Anne became Queen of France in early 1499. This husband, however, was much less restrictive, allowing her to continue to live in Brittany and rule as Duchess, accepting for himself the title of Duke Consort.
She ruled well until 1514. When she died that year of a kidney stone attack, she was just 36, but had been pregnant 14 times, with seven children stillborn. Of the seven who were born alive, only three survived infancy, and only two survived childhood. Her funeral lasted 40 days.
She wished her heart to be encased in a reliquary, and so it was: a beautiful gold one, which was taken to her parents' tomb and then later moved to Saint-Pierre Cathedral. In 1792, during the First French Republic, it was exhumed, emptied, and seized to be melted down. Somehow it was saved, and in 1819 was returned to Nantes. It has remained in Brittany ever since.
Anne was very probably the person who commissioned the beautiful Hunt of the Unicorn tapestries, now on display at the Cloisters Museum in New York City. You can explore them here.