The museum 's most famous piece is a feathered headdress misleadingly believed to have belonged to Moctezuma which has created friction between the Mexican and the Austrian governments .
Moctezuma is the ninth Aztec emperor .
The museum 's most famous piece is a feathered headdress misleadingly believed to have belonged to Moctezuma , the ninth Aztec emperor , which has created friction between the Mexican and the Austrian governments .