The Koh-i-Noor (the "Mountain of Light") is a diamond that was originally 793 carats when uncut.[1] Once the largest known diamond, it is now a 105.6 metric carats diamond, weighing 21.6 grammes in its most recent cut state. In 1852 Albert the Prince Consort had ordered it cut down from 186 carats. The Koh-i-Noor was mined in the state of Andhra Pradesh in India together with its double, the Darya-ye Noor (the "Sea of Light"). The diamond has belonged to many dynasties, including Kakatiyas[citation needed],Rajputs, Mughal, Afsharid, Durrani Empires, Sikh and British. It was seized as a spoil of war time and time again.[2]

In 1849, the diamond was forcibly taken from the Sikh Empire by the British East India Company and became part of the British Crown Jewels when Queen Victoria was proclaimed Empress of India in 1877. The diamond was traditionally known as "Kuh-e nur" in the 19th century after the British conquest of India. The diamond is currently set into the Crown of Queen Elizabeth and is on display at the Tower of London. The diamond originally came from a mine near the temple-town of Dilsuknagar, in the present-day [[Hyderabad] district, region, ofTelangana, India.[3][4]

Legend has it that the stone formed one eye of a Goddess idol installed by the Kakatiyas. The first confirmed historical mention of the Koh-i-Noor by an identifiable name dates from 1526. Babur mentions in his memoirs, the Babur-Nāmah, that the stone had belonged to an unnamed Afghan emperor who was compelled to yield his prized possession in 1294 to 'Alā'uddīn Khiljī. It was then owned by the Tughlaq Dynasty and Lodī Dynasty, and finally came into the possession of Bābur himself in 1526. He called the stone 'the Diamond of Bābur' at the time, although it had been called by other names before he seized it from Ibrāhīm Lodī.

When the Tughlaq dynasty replaced the Khiljī dynasty in 1320 AD, Ghiyāth al-Dīn Tughluq sent his commander Ulūgh Khān in 1323 to defeat the Kākatīya king Prātaparuḑra. Ulūgh Khān's raid was repulsed but he returned in a month with a larger and determined army. The unprepared army of Kakātīya was defeated this time and the diamond was seized by the champion army of the Delhi Sultanate.[5][6]

Both Bābur and Humāyūn mention in their memoirs the origins of 'the Diamond of Bābur'. The last of the Tomaras, Man Singh Tomar, negotiated peace with Sikandar Lodī, Sultan of Delhi and became a vassal of the Delhi Sultanate. Humāyūn's son,Akbar, never kept the diamond with him and later only Shāh Jahān took it out of his treasury. Akbar's grandson, Shāh Jahān was overthrown by his own son, Aurangzēb.

Shah Jahan, famous for building the Taj Mahal in Agra, had the stone placed into his ornate Peacock Throne. His son, Aurangazēb, imprisoned his ailing father at nearby Agra Fort. While in the possession of Aurangazēb, it was cut by Hortenso Borgia, a Venetian lapidary, who was so clumsy that he reduced the weight of the stone to 186 carats.[7] Legend has it that he had the Koh-i-Noor positioned near a window so that Shāh Jahān could see the Tāj Mahal only by looking at its reflection in the stone. Aurangazēb later brought it to his capital Lahore and placed it in his own personal Bādshāhī Mosque. There it stayed until the invasion of Nādir Shāh of Iran in 1739 and the sacking of Agra and Delhi. Along with thePeacock Throne, he also carried off the Koh-i-Noor to Persia in 1739. It was allegedly Nādir Shāh who exclaimed Koh-i-Noor! when he finally managed to obtain the famous stone,[2] and this is how the stone gained its present name. There is no reference to this name before 1739.

The valuation of the Koh-i-Noor is given in the legend that one of Nādir Shāh's consorts supposedly said, "If a strong man should take five stones, and throw one north, one south, one east, and one west, and the last straight up into the air, and the space between filled with gold and gems, that would equal the value of the Koh-i-Noor." After the assassination of Nādir Shāh in 1747, the stone came into the hands of his general, Ahmad Shāh Durrānī of Afghanistan. In 1830, Shujāh Shāh Durrānī, the deposed ruler of Afghanistan, managed to flee with the diamond. He went to Lahore where Ranjīt Singh forced him to surrender it.[8]