This chapter defends the hypothesis that Quechua was brought to Cajamarca during the final expansion of the Huari state (ad 800–900). It offers an alternative for the traditional view that Cajamarca Quechua originated on the central coast of Peru, immediately south-east of Lima. Archaic features of Cajamarca Quechua suggest that it became separated from the main body of the Quechua II branch of the family before it attained its present state of internal differentiation. Possibly the least innovative Quechua II dialect spoken today is that of Ayacucho region, where the Huari capital lay. Together this suggests that population movements underlying the existence of present-day Cajamarca Quechua may have originated in the Huari heartland. This association of Quechua II with Huari prompts a reconsideration of the prevalent view that Ayacucho, including Huari, would have been an exclusive stronghold of the Aymaran languages.