* Description: The Three Brothers jewel was a large rectangular brooch featuring three rectangular diamonds, each arranged side-by-side. It was renowned for its size, beauty, and the combined value of its three principal diamonds.
* History: Its origins are debated, but it's believed to have appeared in Europe in the late 14th or early 15th century.
* It was owned by powerful figures throughout history, including the Duke of Berry, Jacques Coeur (a wealthy French merchant), the Fugger family (bankers), and eventually the English Crown.
* Disappearance: The jewel disappeared from historical record after being sold by Henrietta Maria, the widow of Charles I of England, sometime after 1649. Its exact fate is unknown.
* Possible Identification: Some theories propose that one or more existing diamonds may have been cut from the Three Brothers. One popular theory is that the Wittelsbach-Graff Diamond, a blue diamond, might have originated from it. However, these theories are difficult to confirm definitively.