Cosimo III de' Medici, Grand Duke of Tuscany

Cosimo III de' Medici (14 August 1642 – 31 October 1723) was the penultimate Grand Duke of Tuscany. He reigned from 1670 to 1723, and was the elder son of Grand Duke Ferdinando II of Tuscany. Cosimo's fifty long reign, the longest in Tuscan history, was marked by a series of regulatory laws. His reign also saw Tuscany's bad finances become even worse. He was succeeded by his elder surviving son, Gian Gastone de' Medici, when he died, in 1723.

Cosimo III
Cosimo in granducal robes, with Tuscan regalia
Grand Duke of Tuscany
23 May 1670 – 31 October 1723
Predecessor	Ferdinando II
Successor	Gian Giastone
Born	14 August 1642 Pitti Palace, Florence, Tuscany
Died	== Cosimo III De' Medici, Grand Duke Of Tuscany Media == Ferdinando II de' Medici, Grand Duke of Tuscany, Cosimo III's father, and Vittoria Della Rovere, his mother, by Justus Sustermans Marguerite Louise d'Orléans, Cosimo's wife, after Louis Edouard Rioult Cosimo around 1660, by Sustermans Rembrandt, Self-portrait, 1668–1669, Galleria degli Uffizi, Florence A contemporary piastra bearing the effigy of Cosimo III. Latin inscription: COSMVS III D[EI] G[RATIA] MAG[NVS] DVX ETRVR[AE]. "Cosimo III, by the Grace of God, Grand Duke of Etruria (Tuscany)" Cosimo III, Grand Duke of Tuscany, engraving by Adriaen Haelwegh before 1691, from the collection of the National Gallery of Art Ferdinando de' Medici, Cosimo's elder son, after Niccolò Cassana. Cosimo III in old age, by Jan Frans van Douven Portrait of Gian Gastone de' Medici The Grand Duke in the latter years of life 31 October 1723(1723-10-31) (aged 81) Pitti Palace, Florence, Tuscany
Burial	Basilica of San Lorenzo, Tuscany
Consort	Marguerite Louise d'Orléans
Issue Detail	Ferdinando, Grand Prince of Tuscany Anna Maria Luisa, Electress Palatine Gian Gastone, Grand Duke of Tuscany
Full name Cosimo de' Medici
House	House of Medici
Father	Ferdinando II de' Medici
Mother	Vittoria della Rovere
Religion	Roman Catholicism

He married Marguerite Louise d'Orléans, a cousin of Louis XIV. It was a bad marriage and Marguerite Louise eventually left Tuscany to remain at the Convent of Montmartre in Paris. Together, they had 3 children. In later life, he tried to have Anna Maria Luisa recognised as heiress of Tuscany, but Charles VI, Holy Roman Emperor, would not allow it. Tuscany passed it to the House of Lorraine in 1737.

Issue

Cosimo III had three children with Marguerite Louise d'Orléans, a granddaughter of Henry IV of France:

• Ferdinando de' Medici, Grand Prince of Tuscany (b.1663 d.1713)
• Anna Maria Luisa de' Medici, Electress Palatine (b.1667 d.1743)
• Gian Gastone de' Medici, Grand Duke of Tuscany (b.1671 d.1737)

• 14 August 1642 – 23 May 1670: His Highness The Grand Prince of Tuscany
• 23 May 1670 – 5 February 1691: His Highness The Grand Duke of Tuscany
• 5 February 1691 – 31 October 1723: His Royal Highness The Most Serene Grand Duke of Tuscany

Cosimo III's official style was "Cosimo the Third, By the Grace of God, Grand Duke of Tuscany."