The Nahuatl language is one of Mexico’s official national languages, and as the language of the Aztecs, it holds a special place in the nations national imagination. But it is also the language of many indigenous micro-nations scattered throughout the country, and even across the borders into the US. So what happens when the Mexican state that has long worked to eradicate indigenous languages decides to support and revitalize indigenous languages, and does this help or damage the ability of indigenous communities to keep their languages alive? Based on long-term ethnography, this book is about how the Nahuatl language plays a role in the political life of different kinds of communities - from the Mexican nation, to indigenous towns and regions, and to the Mexican diaspora in the US. It is also about how politics play a role in the life of a language. It argues that to understand why some indigenous languages become endangered and disappear while others remain vital community languages, we must understand the political relations between the speech communities and the national community, and the way that the language is integrated into the fabric of indigenous community life. Engaging with indigenous scholarship on political sovereignty of indigenous peoples it introduces the concept of “semiotic sovereignty” to analyze the semiotic relations between indigenous political communities and nation state politics. It argues that for indigenous communities it is of crucial importance to control its own semiotic resources, prominently including language.