Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

This empire's merchants used quills filled with gold dust as currency; some of those merchants were used as disguised spies. Commoners in this empire wore a full-length cloak called a tilma, over which men wore shoulder pouches. These people were divided into clan-like units called calpulli. After a Sparta-like mandatory military education, its men could capture four opponents in battle to become "eagle knights." Long strips of mud were used as "floating gardens" around this empire's central (*) lake. Seven causeways led into its canal-laden capital, where a spicy liquid chocolate was first brewed and two shrines sat atop the Templo Mayor pyramid. For 10 points, name this empire which sacrificed human captives under emperors such as Montezuma.
History