Is there a connection between territorial expansion and human sacrifice? explain.

The common consensus—outside academic circles, at least—is that the Aztec empire, like most indigenous American nations, crumbled under the combined force of colonial subjugation and imported European diseases. And while these factors certainly played substantial roles in the Spanish conquest of Mexico, another theory considers a fascinating aspect of Aztec society: human sacrifice.

And few things fascinate anthropologists and archaeologists, amateur and professional, than ritualistic slaughter. It can’t be helped. It’s the very same morbid appeal that HLN true-crime documentaries capitalize on. Death—the weirder, the better—is always enthralling.

Yes there is: A deity of the Aztecs needed regular "feed" of fresh human hearts. Aztecs would rather offer these sacrifices from neighbours, which is one of the reasons that explains their territorial expansion.

its many islands, high mountains, and remote peninsulas isolated population centers.

it affected it because the kingdoms (with trade) slowly got richer and richer.