The Black Prince's Ruby

When is a ruby not really a ruby?  When it's a spinel.  A ruby is composed of corundum or aluminum oxide.  A spinal contains magnesia, iron and chromium.  Centuries before the Periodic Table and Mohs Scale of Hardness, an opaque red gemstone was a ruby.  Because most of these rubies at the time came from what is now Tajikistan and were called balas rubies.  The Black Prince's Ruby and the Samarian Spinel in the Iranian Crown Jewels are two of the largest red spinels in the world.  And they both suffer from an unfortunate man-made flaw of a hole drilled through them. 

The ruby/spinel surfaces in the 14th century in the possession of Abu Said, the then-Prince of Granada, a Moorish kingdom in Spain.  Islamic traders were active throughout the Mediterranean and adjoining countries, so it's entirely plausible that a large uncut spinel was passed along the various trade routes and wound up in Abu's collection.  It was Abu's misfortune to make war with Pedro of Castile, known to history as Pedro the Cruel.  When Abu came to Seville to discuss peace, Pedro had him murdered instead.  The stone was found among Abu's possession and became Pedro's on the spot.  Then Pedro's brother rebelled against him and he had to call on foreign troops from England to help put down the revolt.  These men were led by Edward, the Black Prince, one of the foremost military commanders of his time.  Edward laid eyes on the ruby and demanded it as a personal tip for his services.

Edward took the ruby home to England, where it remained in the royal possession until its first famous outing at the Battle of Agincourt in 1415.  Henry V used the stone as part of the embellishment of his helmet.  It was at this time that someone drilled a hole in it to affix a spike or hook that would keep the stone on the helmet in the heat of battle.  By then it was already known as the Black Prince's Ruby.  Richard III may also have worn the ruby as an adornment on his helmet.  It came into the possession of the Tudors and was set in the elaborate crown created by Henry VIII for his coronation.  This crown, known as the Tudor Crown, appears in several portraits of Tudor and Stuart monarchs.  Unfortunately, during the English Civil War it, like most of the other Royal Regalia, was scrapped for metal and the gemstones sold.

Someone, it isn't known who, bought the ruby and later presented it back to Charles II.  It wasn't until the reign of Victoria that it was set in a brand new Imperial State Crown which she had commissioned for her own coronation.  It was then that the unsightly hole was plugged with a real ruby.  The stone resides in the front of the Imperial State Crown, above the diamond Cullinan II on the rim.