Despite Turkish general staff's significant efforts to create an ideologically cohesive officer corps through highly meticulous recruitment and promotion practices and frequent purges since the early republican period and more significantly after the 1970s, divergent views and ideological pluralism has never ceased to exist within the Turkish military behind its monolithic façade. For instance, the July 15 coup has recently unveiled that there have existed various religious groups within the ranks despite the military’s so-called secularist institutional identity. To what extent this diversity has reflected that of Turkish society? And what does this mean for the military-society relations? Despite paradoxical views on the Turkish military’s social makeup, there are few or no empirical works that examine the Turkish officers ideological, ethnic, religious, and demographic origins, whether they vary across services and branches of the military, and whether they align with those of the Turkish society. Also, literature is devoid of a work that explores the purges from the Turkish military, which could help us understand what kind of officer corps has been intended in terms of its ideological and demographic makeup and if this has changed over time. Drawing on original historical demographic and purge data on Turkish officers, collected by the author himself from the military libraries and archives in Istanbul and Ankara and from national newspapers, this paper examines the social composition of and Turkish officer corps and variations it has undergone since the early republican period but focusing on the post-1980 period. Complemented with the analysis of the changes in the military laws and regulations regarding recruitment, performance management, and discipline, my research elucidates what kind of officer been sought to be retained, promoted, favored, or excluded and dismissed within the Turkish military system. These measurable criteria for dismissals and promotions as well as for the punishments and incentives towards the military's own personnel help us understand the continuities and changes in Turkish military ethos, institutional identity, and self-conception. My research finds that the Turkish military has not been a socially representative institution in terms of ethnic, religious, socioeconomic origins as well as the geographical and urban-rural distribution of its personnel—nor has it intended to be, despite the persistent presence of some diversity within its ranks. Additionally, it finds that the demographic and cultural gap between the Turkish military and society has contributed to the long-standing civil-military troubles of Turkey.