This dissertation analyzes the liturgical commemoration of earthquakes in Constantinople ca. 400-600 CE. Earthquake commemorations were some of the earliest rites created locally for the city's liturgy. This thesis argues that analysis of this rite, its origins, and its contested reception history illuminates the theological, environmental, and political concerns that shaped the early liturgy of Constantinople.The thesis begins with a reconstruction of the original ritual pattern and theology of the commemoration rite and its evolution. It was comprised of readings, hymns, and a long procession that mimicked the evacuation route taken during earthquakes. Over the course of its performance, which lasted from evening until the afternoon on the next day, the rite depicted earthquakes as manifestations of divine wrath against the people for their unfaithfulness, for which collective repentance is prescribed as an effective response. Next, the thesis locates the origins of the liturgical rite in a ritual repertoire of prayer and supplication that emerged from spontaneous, popular responses to earthquakes in Constantinople. Prior to the practice of commemorating earthquakes liturgically, the late-fourth and early-fifth century preachers Severian of Gabala and John Chrysostom drew from this ritual repertoire to make theological sense of Constantinopolitan earthquakes. They framed earthquakes as divine manifestations and placed Constantinople at the center of a narrative of God's providential guidance of history. The thesis then analyzes the five earthquakes commemorated between 438 and 557. With its call for mass repentance in the face of God's wrath, the commemoration rite challenged Constantinople's ambitions as the new capital of the Roman Empire. Those dedicated to augmenting Constantinople's political and ecclesiastical power disputed the theology of earthquakes as signs of divine wrath, and reframed local earthquakes as signs of divine blessing upon the city and its ambitions.  Analysis of the liturgical commemoration of earthquakes illuminates hitherto unexplored tensions between Christianity and classical Roman ideology at play in the formation of the liturgy of Constantinople. By showing how the liturgy connected environmental, theological, and political concerns, this dissertation pursues new avenues for exploring the role played by the natural environment in the shaping of Christian ritual and liturgy.