There are many claims to the Koh-i-Noor diamond.
The jewel may have passed through hands and nations for as many as 5000 years — some think ancient Mesopotamian texts make reference to the Koh-i-Noor as early as 3200 B.C. It may have once been a monstrous 793 carets, before a jeweler's maladroitness and a few subsequent refinements chopped it to the mere 109-caret chunk it is today. The Moguls possessed it in the 16th Century, only to lose it to the Iranians, who then lost it to the Afghans. It later went to the Sikhs and ended up with the British. And while the stone carried with it a warning that it would bring harm to its owner, Queen Victoria paid it no heed. It circulated through the British crown jewels until finding a home in the coronation crown of Elizabeth, Britain's most recent Queen Mother.
Current Status: Many lay claim to the Koh-i-Noor, including the Taliban, who trace its origin in India through Afghanistan in ancient days. Indian Sikhs have asked for the diamond back too, as they were the most recent holders before the British. For their part, the British are deaf to these claims, arguing since the diamond has passed through so many hands for so long, they have just as much right to the stone as anyone.