Cosimo III de' Medici, Grand Duke of Tuscany

Cosimo III became Grand Duke in 1670, the elder son of Ferdinando II and sixth Medici to rule Tuscany. His marriage to Marguerite Louise d'Orléans, cousin of Louis XIV, was solemnized by proxy at the Louvre in 1661 and proved disastrous; she eventually abandoned Florence for a convent in Montmartre. They had three children: Ferdinando in 1663, Anna Maria Luisa in 1667, and Gian Gastone in 1671. His reign was marked by laws regulating prostitution and May celebrations, and by Tuscany's slide into previously unknown economic lows. When it became clear his sons would produce no heirs, he tried to make Anna Maria Luisa universal heiress, but Charles VI refused to alter the succession of an imperial fief. Cosimo died in 1723 and was succeeded by Gian Gastone; fourteen years later the Medici line ended and Tuscany passed to Lorraine.