They turned for allies to the Catholic elite of Paris and to people close to Napoleon III.

ECONOMIST: Christian believers

Distinguished gentlemen have been buying bespoke suits on London's Savile Row for centuries, from Churchill to Napoleon III.

FORBES: Bespoke

The classification came about thanks to Napoleon III, who ordered a group of wine brokers to come up with a list of the best Bordeaux in time for the Paris Exposition, a sort of national trade fair.

WSJ: Getting to the Bottom of Bordeaux Wines | On Wine by Lettie Teague

Napoleon III's plan was to instill a monarchy over Mexico and "have that monarch cooperate with the Confederacy, " Hayes-Bautista said.

CNN: STORY HIGHLIGHTS

The ring is from the collection of Emperor Napoleon III and Empress Eugenie, according to the auction house.

FORBES: Connect

As a member of the avant-garde in mathematics in France in the 1930s he made his name as a founder of the Bourbaki group, which owed its moniker to a prank theorem named after a general in Napoleon III's army.

ECONOMIST: Andr�� Weil