26 January 1905: the world’s largest diamond, the Cullinan, is discovered

Frederick Wells, manager of the Premier mine in South Africa, couldn't believe his luck when on 26 January 1905 (some sources put it a day earlier), he stumbled upon the largest diamond ever discovered a huge 0.6kg gem, weighing 3,106.75 carats. It was compared to an oversized lump of light-coloured barley sugar, and was presented to the mine's owner Sir Thomas Cullinan.

No buyer could be found, however, so two years later the regional Transvaal government decided to buy the diamond for £150,000 and present it to King Edward VII for his birthday. Transporting such a precious rock attracted rather a lot of unwanted attention, so it was smuggled onto a steamship and kept under guard.

But that was an elaborate ruse. The diamond on the steamship, drawing all the attention from the press, was a fake. The real Cullinan diamond travelled by recorded post with a mere three-shilling postage stamp affixed to its unsuspecting parcel.

After being presented to the King in November 1907, the diamond was sent to Joseph Asscher in Amsterdam, widely considered one of the best diamond cutters in the world. For several months, he studied the impurities of the gem to know exactly where to make his cuts. Incidentally, a large flat surface on the diamond led some to believe that it had been broken at some point, and that a piece almost as big remained somewhere. If so, it's never been found.

Asscher's first attempt to cut the diamond, according to legend, resulted in his chisel sheering in half. When he did manage to break it, he fainted in his studio. After eight months, the Cullinan had been cut into nine principal stones', the largest of which is the Great Star of Africa, which remains the largest polished white diamond in the world.

Today, it sits in the Queen's sceptre along with the next biggest fragment, the Cullinan II, which is nestled in the Imperial State Crown, both forming part of the Crown Jewels.