New York ? Gorgeous textiles, ornate tiles and elaborate books are all traced back to a gang of invading warriors.

The items are part of an exhibit opening Tuesday at the Metropolitan Museum of Art called “The Legacy of Genghis Khan: Courtly Art and Culture in Western Asia 1256-1353.”

The show examines the artwork and traditions that emerged after the Mongol invaders won the battles that created a diverse empire that stretched from China to Hungary, from the Pacific Ocean to the Black Sea.

It was a well-run empire, with the Mongols establishing themselves as rulers of various regions but quickly tapping local residents to serve under them in the bureaucracy. They also set up an efficient system of communicating across the vast territory with Pony Express-like stations of well-rested horses.

And instead of carrying papers to prove identification, envoys wore metal “passports” around their necks or on their clothing. One on display is made of cast-iron and silver-inlaid metal and has an inscription that reads, “By the strength of eternal heaven, an edict of the Emperor. He who has no respect shall be guilty.”