Discovered in 1701 by an Indian slave near Golconda, the Regent diamond weighed 410 carats in the rough.

Once owned by William Pitt, the English Prime Minister, this diamond diamond was cut into a cushion-shaped brilliant of 140.50 carats. Until it was sold to the Duke of Orleans, it was called the Pitt diamond.

It was then renamed the Regent diamond and set in the crown Louis XV wore at his coronation. After the French revolution, it was owned by Napoleon Bonaparte who set the diamond in the hilt of his sword.

The Regent diamond is now on display in the Louvre.