Cosimo III de' Medici (1642-1723), Grand Duke of Tuscany from 1670-1723, was the eldest surviving son of Vittoria della Rovere and Ferdinando II de' Medici, Grand Duke of Tuscany. He was the brother of Fernando II de' Medici. In 1661 he married Marguerite Louise d'Orléans, a granddaughter of Henry IV of France.

During his reign, Cosimo seemed to be obsessed with religion and sex, making many laws against prostitution.  He also persecuted the Jewish population of Tuscany; sexual intercourse between Jews and Christians was proscribed and Christians could not work in establishments owned by Jews.  His son and successor, Gian Gastone, repealed Cosimo's Jewish persecution laws.

Cosimo died without any ostensible heir, bringing about the War of the Spanish Succession. He left a Tuscany one of the poorest nations in Europe, the treasury empty and the people weary of religious bigotry.

The medal celebrates the extent of the grand duchy, including the cities of Florence, Siena and Pisa.