1571 - April 10, 1599: Age 28?
Gabrielle d'Estrées was certainly one of the most beautiful women in the world when she became the lover of the King of France in 1591. In those days it was perfectly normal for a king to have an acknowledged mistress, even when married to someone else, as Henri was. Gabrielle followed the King everywhere, even in war, pregnant, living in his tent near the battlefield and making sure his creature comforts were in place. They adored each other.
The big issue of the century, of course, was the Reformation: most of the rich and powerful of Europe circled the issue like wolves looking for ways to use religious disputes to strengthen their fortunes. Henri was an exception: born Protestant, he converted to Catholicism when he became King of France, and worked for his whole life to bring about peace and religious tolerance for his kingdom. For a time, he succeeded.
His first marriage was unhappy and, mindful of the need for an heir, he tried to obtain an annulment, planning to marry Gabrielle, who had already produced three children for him. The plan came to nothing in 1599. Gabrielle, pregnant with their fourth child, suddenly developed eclampsia, a serious complication in which the mother suddenly begins convulsing. Today good prenatal care means the danger signs can be caught and the situation controlled long before it becomes life-threatening. Obstetrics in the 16th century were different. Gabrielle fell into convulsions, gave birth to a stillborn son, and died the next day, before the King (who was elsewhere) could reach her side. He was devastated, and wore mourning (unheard of for a mistress) and gave her a royal funeral.
No mention of this amazing woman would be complete without taking the opportunity to show Gabrielle d'Estrées et une de ses soeurs, which now hangs in the Louvre. That's her on the right, holding Henry's coronation ring, which he gave her. I guess this was the 16th century equivalent of a shoot for Playboy.