"Cosimo III de´ Medici (14 August 1642 – 31 October 1723) was the penultimate (sixth) Medici Grand Duke of Tuscany. He reigned from 1670 to 1723, and was the elder son of Grand Duke Ferdinando II. Cosimo´s 53-year-long reign, the longest in Tuscan history, was marked by a series of ultra-reactionary laws which regulated prostitution and banned May celebrations. His reign also witnessed Tuscany´s deterioration to previously unknown economic lows. He was succeeded by his elder surviving son, Gian Gastone, when he died, in 1723.
He married Marguerite Louise d´Orléans, a cousin of Louis XIV. The marriage was solemnized by proxy in the King´s Chapel at the Louvre, on Sunday, 17 April 1661. It was a marriage fraught with tribulation. Marguerite Louise eventually abandoned Tuscany for the Convent of Montmartre. Together, they had three children: Ferdinando in 1663, Anna Maria Luisa, Electress Palatine, in 1667, and Gian Gastone, the last Medicean ruler of Tuscany, in 1671." - (en.wikipedia.org 06.11.2019)
)
