Fascinating history of art heists...

... from the Mona Lisa to a gold toilet, and now the Louvre's royal jewels

- PENELOPE JACKSON

The world's largest art museum, the Louvre has about half a million objects in its collection, with about 30,000 on display, and sees on average 8 million visitors per year.

That's big on any scale, with a lot of people and objects to keep watch over. And Sundays are particularly busy.

In a cleverly conceived operation, four men wearing fluorescent vests pulled up at the Louvre in a flat-decked truck at 9.30 Sunday morning. Quickly setting to work, they raised an extendable ladder to the second storey. Climbing it, they cut through a window, entered the Galerie d'Apollon and, brandishing power tools, helped themselves to nine exquisite objects.

The objects taken were France's royal jewels, formerly belonging to the Empress Eugénie, Napoleon III's wife and arts patron.

This is where it gets tricky for the thieves: what can you do with these priceless objects? They can't wear them — too big and glitzy to go unnoticed-and they can't sell them legitimately, as images are all over the internet. The best-case scenario, from the thieves' perspective, is to break them down, melt the precious metals and sell the gems separately.

Empress Eugenie's crown, which the perpetrators took and subsequently dropped as they fled the scene on motor scooters, contains eight gold eagles, 1,354 brilliant-cut diamonds, 1,136 rose-cut diamonds and 56 emeralds. In short, this amounts to a sizeable stash of individual gems to try and sell.

Timing is everything