Histories of the conquest often end with the fall of Tenochtitlan, but the forging of New Spain required decades of continued military invasions in which central Mexicans, in particular, played leading roles. This chapter examines how the Tlaxcalteca and other Native allies petitioned the Spanish Crown for certain rights and privileges, as a form of negotiation within a system of domination and oppression, even sailing across the Atlantic to Spain multiple times to do so in person. Imperial rule and religious conversion could occasionally be challenged or proactively shaped by Mesoamericans, generating hybrid forms of religious belief, public spectacles, art, architecture, diet, and personal adornment, all inscribed on Mexico’s natural and cultural landscape. Such exchanges also crossed the Atlantic, and eventually the Pacific, to begin a truly global world history.