Throughout the twentieth century, Azeri Turkish was intermittently banned, occasionally tolerated, but always marginalized in relation to Persian, which was perceived as the unifying, defining, essential language of the nation. Despite the substantial population of Azeri Turkish speakers in Iran—the largest linguistic minority—any attempt to teach the language publicly or to publish in Azeri Turkish has often been regarded, even to this day, as a highly political act of dissidence. Historical analysis of Azeri Turkish texts and a review of policies in language teaching, publication, and censorship within Iranian Azerbaijan reveal a symbiotic but simultaneously paradoxical interaction between this mother tongue and the official master language.