The bronze medal shows the 78-year-old Cosimo III de' Medici in profile to the right, dressed in parade armour with the Florentine lily and the cross of the Order of St Stephen on the chest. The reverse shows St Joseph offering the Florentine lily to the Christ Child, with six flying angels holding the Medici palm above. Cosimo was sincerely pious and played a central role in promoting the cult of St Joseph, to whom he was particularly devoted. In a solemn ceremony on 18 December 1719, the Grand Duke proclaimed Joseph the patron saint of Tuscany. The medal was commissioned to Giovacchino Fortini in 1720 to commemorate the event.

Giovacchino Fortini (1670-1736) was one of the leading Florentine sculptors of the late Baroque period. Born in Settignano, near Florence, he came from a family of stonemasons and ornamental sculptors. He later trained in the workshops of the sculptors Carlo Marcellini and Giuseppe Piamontini. Fortini was a versatile artist, working in a variety of materials from marble and bronze to stucco and terracotta, and he also worked as an architect.
In portraiture, he developed a distinctive and highly recognisable style, which is well represented in his medals. The portrait of the Grand Duke on the obverse clearly shows the sculptor's mastery of capturing both the physical appearance and the character of the subject. The sculptor wanted to portray the features of the old sovereign truthfully. Indeed, he showed no desire to hide the Grand Duke's pronounced bags under the eyes, the sagging skin under the chin and his baldness, all clear signs of the passage of time. The decision to reproduce in detail, without idealising concessions, every feature of the Grand Duke's head does not detract from the solemnity of the image: the noble spirit of the portrait shines through in all its strength, also thanks to the proud pose and the monumental, almost heroic armour he wears (Bellesi, Visonà 2008, pp. 177-178).

In the Grand Duchy of Tuscany, from the end of the seventeenth century, the casting of medals experienced a new period of prosperity, directly promoted by Cosimo III. From a young age, he had developed a deep interest in the art of the medal. He soon conceived a project for the renewal of medal-making in the Grand Duchy, probably inspired by the results achieved in this field in capitals such as London and Paris, which he had the opportunity to visit during his youthful travels in Europe.

In its multifaceted nature as a work of art, a monument, a document and a means of scholarly communication, the medal enjoyed great success in the 18th century. As an instrument of celebration of the individual, it was well suited to performing representative functions for those in power. Through their inscriptions and figurative representations, medals were able to convey a specific public image of the person portrayed, as well as clear messages about his or her ambitions, values, talents or history.