The Ta'ziyeh, a poetic and musical ritual performance, emerged from Shīʿa mourning traditions and is centered on the events of ʿĀshūrā. Blending religion, art, ethics, and social relations, this ritual performance reached its zenith during the fifty-year reign of Nāṣir al-Dīn Shāh Qājār, evolving from a simple, spontaneous form into a multifaceted, organized "ritual performance institution" at the heart of Iran's urban and political life. This period, coinciding with the initial signs of modernization and structural transformation, provided an unparalleled context for the flourishing of this ritual performance. Adopting a qualitative approach and a historical-documentary method, the present study examines the social functions of the Ta'ziyeh in the Nāṣirī era and explores its connection to structures of power, the reproduction of collective identity, and social cohesion. The theoretical framework is grounded in a synthesis of Victor Turner's concepts of "liminality, communitas, and anti-structure" and Ferdinand Tönnies' dichotomy of "Gemeinschaft/Gesellschaft", formulated through the analytical model of the "liminal institution". The findings reveal that the Ta'ziyeh in the Nāṣirī period functioned as a "liminal institution" in which the rationality and formal structure of "Gesellschaft" (the Takīya Dawlat, state funding, professional troupes) served to reproduce the most affective elements of "Gemeinschaft" (solidarity, shared faith, traditional bonds). By creating a liminal space, this institution provided an experience of communitas for spectators from diverse social strata; however, this communitas constituted a "controlled anti-structure" whose egalitarian energy was harnessed within the meticulously managed space of the Takīya Dawlat, and through the symbolic presence of the Shah, transformed into a source for the reproduction of monarchical legitimacy. Thus, the Ta'ziyeh in the Nāṣirī era functioned as a "ritual-political technology" that, by intertwining modern logic and traditional structures, engendered a distinct form of "ritualistic modernity" in Iran, playing a decisive role in reproducing Shīʿa-Iranian collective identity and legitimizing the ruling political structure on the threshold of Iran's entry into modern relations.