FAMOUS DIAMONDS
MIRROR OF PORTUGAL
At various times three Royal Houses of Europe owned this rectangular table-cut diamond.
After the death of the Cardinal King Henry of Portugal in 1580 his illegitimate nephew, Dom Antonio de Castro, known as the Prior of Crato, proclaimed himself King. Philip II, King of Spain refused to recognize Dom Antonio's sovereignty and dispatched an army which defeated him in 1580 and led to the annexation of Portugal to Spain. The vanquished claimant then went to Paris: with French assistance he sent a naval expedition to the Azores, where he was recognized as the King of Portugal, but was defeated by the Spanish squadrons. Dom Antonio escaped to London, taking with him some of the Portuguese Crown Jewels. In his absence he was condemned to death, one of the charges being that he had unlawfully taken the jewels with him. Among the items was the 'Mirror of Portugal', then reputed to have weighed around 30 carats. Dom Antonio hoped to interest Queen Elizabeth 1 in the jewellery, thereby raising funds sufficient to enable him to continue the struggle against his adversary. The Queen sent a fleet which effected a landing near Lisbon in 1589 but the expedition proved a costly failure. Then feeling that she had done enough to help Dom Antonio, Elizabeth kept the Portuguese jewels; the 'Mirror of Portugal' was mounted in a chain of gold, enameled and surrounded by flowers. Impoverished and in poor health, Dom Antonio returned to Paris where he died in 1595.
In 1623 the Prince of Wales, afterwards King Charles 1, traveled to Spain to make an alliance with that country; it was intended that it should be sealed by his betrothal to the Infanta. His father James 1, ordered that a selection of the finest jewels in the Tower of London would be available to his son so that he might make a good impression. The 'Mirror of Portugal' was chosen, set with a large pearl as a pendant. In the event the Prince's suit proved to be unsuccessful, and in 1625, as Charles 1, he married Henrietta Maria, daughter of Henry 1V and Marie de Medici of France. Van Dyck painted a portrait of the Queen which depicts her wearing a brooch containing the 'Mirror of Portugal' and four lesser diamonds. This picture is now in the Hermitage Museum in Leningrad. Almost from the outset of his reign (1625-49) Charles 1 was short of money, the situation rendered even more difficult by his dispute with the parliamentarians and the ensuing civil war. For her part Queen Henrietta Maria, who was devoted to her husband, showed the courage and determination that were natural to the daughter of two such strong-minded parents. On the other hand the Queen never understood English politics and thought that a military coup would overthrow the parliamentarians. In 1644 she sailed to the Netherlands to sell jewels and raise funds for the King, returning with munitions. Among items from the Treasury which the Queen took with her were the 'Mirror of Portugal' and the 'Sancy': henceforth for a century and a half these two diamonds were to pursue the same historical path.
Neither diamond was sold in the Netherlands, so the Queen contracted loans with the Duke of Epernon amounting to 427,566 livres. Because he feared that he might not be repaid the money, the Queen pledged the 'Mirror of Portugal' and the 'Sancy' as surety. Alas, the Duke's fears proved to be justified as the Queen was unable to repay the loans; therefore, in return for the extinction of 360,000 livres of the debt he was permitted to keep both diamonds. He sold them to Cardinal Mazarin, the 'Sancy' becoming 'Mazarin No 1' and the 'Mirror of Portugal' becoming 'Mazarin No III' in his famous collection. Cardinal Mazarin bequeathed them to the French Crown when he died in 1661.
At some stage the 'Mirror of Portugal' was recut, most likely after its purchase by Cardinal Mazarin, since in the 1691 Inventory of the French Crown Jewels its weight was recorded as 25 3/8 carats. It was then valued at 150,000 livres. The diamond must have been recut a second time because in the inventory of the Crown Jewels made one hundred years later its weight had been reduced to 21 1/8 carats but its value had increased to 250,000 livres.
The 'Mirror of Portugal' was one of the jewels stolen during the infamous robbery of the Garde Meuble that occurred on the night of September 1792. Since that melancholy episode there has been no trace of this historic stone.