The Kurdistan Workers' Party (PKK), established in embryonic form in the mid-1970s, has been one of the most successful insurgent organizations in contemporary times. While the PKK failed to militarily defeat the Turkish state, it has persisted as a resilient and popular organization despite the capture of its leader, changing geopolitical conditions, and democratization trends in Turkey. Moreover, the PKK has become the only organization that has effectively challenged the authority of the Turkish state and developed strong appeal among Kurdish citizens of Turkey even if it was just one of the many Kurdish radical organizations that mushroomed throughout the 1970s. This paper aims to understand how the PKK has become the hegemonic Kurdish organization in Turkey. It analyzes the evolution of the PKK from its foundation in the mid-1970s to the late-1980s when it became a serious military threat to the Turkish state. The existing explanations of the rise of the PKK either put forward conspiracy theories (i.e., the linkages between the PKK and the Turkish security services) or the waves of repression following the 1980 coup. This paper offers a more satisfactory and accurate account based on two premises. First, the PKK correctly diagnosed that persistent socioeconomic inequalities and power of landlords and tribal sheiks created a fertile ground for insurgent recruitment. Next, the PKK also realized only an armed struggle that instills confidence among poor peasants and urban proletariat would mobilize public support. As a result, the PKK emerged as a mass movement even before the 1980 coup. The paper is based on two conceptual approaches: 1) it goes beyond a dichotomy of state-society and analyzes state-society interactions in geographical areas where the PKK was active, and 2) it explicitly recognizes the plasticity and porous nature of ethnic identity and shows how the PKK developed a new understanding of Kurdishness that both expanded and limited its appeal. Data for this paper comes from a rich array of sources: 1) a newly constructed database that includes biographical information about hundreds of PKK militants as well as members of other Kurdish radical organizations (e.g., KUK), 2) personal interviews with and memoirs of Kurdish political activists, 3) issues of the PKK's monthly magazine Serxwebun that started its publication in January 1982 and other PKK documents, 4) court documents from the trials of Kurdish activists, and 5) Turkish newspapers and magazines from the period.