The city of Valdivia in Chile was founded c. 1552 by Spaniards at the site of a previous indigenous settlement. After that, several rebellions and conflicts followed one another in quick succession, and by the seventeenth century the area of Valdivia became one of the most heavily fortified within the Spanish empire, effectively creating a colonial frontier. This chapter discusses the idea of colonial borderlands and mestizaje by confronting textual discourses on violence and resistance with the archaeological evidence of everyday life in the area around Valdivia. In doing so, it brings the agency of native communities (the Reche-Mapuche, and the Huilliche) to the forefront of the discussion, and provides a more nuanced and plural conception of mestizaje in colonial Latin America.