18th Century cameo gem set ring depicting Louis XVI and Marie Antoinette

Louis XVI and Marie-Antoinette were married in 1770 and reigned in France between 1774 and 1789, the year when the French Revolution started. They were executed by guillotine in 1793. During their reign, they were frequently portrayed in miniatures, ceramics, and hardstone cameos. Just as in our days one might receive a signed photograph of a famous person, in those days, works with their faces on jewellery would be given to their friends, political and diplomatic allies, and courtiers. Most of the portraits were of either the king or queen, and double portraits of this kind are therefore rare.
Some experts claim that rings like this one (we know of the worldwide existence of three similar rings) were made specially to commemorate the birth of Louis XVI and Marie-Antoinette's eldest child, Marie Thérèse of France, in 1778. Another factor that could have influenced the scarcity of such rings is that, after the Revolution, possession of such jewellery would have been regarded as evidence of treason.
When you check the describing page of this royal ring, you will not only find more pictures and even a movie of this ring but you will also find a copy of their last letters before being beheaded by the guillotine, plus a translation of these letters.