It's rumored that King Philip IV of Spain purchased the jewel and included it in the dowry of his teenage daughter, Margaret Teresa, in 1664.

传说，西班牙国王菲利普四世曾于1664年买下这颗钻石，并把它作为女儿玛格丽特·特蕾莎的嫁妆。

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The identity of the painting's subject is not known, but it is thought the balding, bearded man in a stiff, starched collar may be Juan Mateos, King Philip IV of Spain's master of the hunt.

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Diego Rodriguez de Silva y Velazquez (1599 - 1660) was the leading artist in the court of King Philip IV of Spain, and is best known for his portraits of the royal family, including his masterpiece, Las Meninas.

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Some are distinguished by design or material, such as the nearly two pounds of solid gold that King Philip II of Spain attached to his profession of fealty to Pope Paul IV in 1555.

WSJ: Lux in Arcana | Capitoline Museum | The Papacy's Private Papers | By Francis X. Rocca