This study investigates "Prateritumschwund," one of the most salient developments in the Upper German dialect area during the Early Modern period. Drawing on a wide range of text types originating in Nuremberg and its surrounding areas from the 13th to the 17th centuries, this study tests various hypotheses put forward as alleged causes of preterit loss: schwa apocope, schwa syncope, and the increase in preference for a periphrastic perfect tense across several languages in Central Europe. While the data do not reveal a strong correlation between preterit loss and any one of these linguistic developments, they suggest a possible relationship to multiple factors. The repeated demographic declines and subsequent repopulation between the 13th and 17th centuries in Nuremberg certainly could have played a role in the ongoing development of the urban vernacular. After disruptions such as repeated visitations of the Black Death, extremely high levels of mortality and compensatory immigration over the centuries created an unstable social landscape and may have contributed to a koineization process in Nuremberg. As a result of the demographic upheaval, the urban population of Nuremberg was very diverse from a dialectal perspective. This welter of dialect forms undoubtedly encouraged the development of the new urban vernacular characterized by widespread schwa apocope and syncope and the development of analytical verbal constructions developed. One manifestation of this trend toward analytical verbal construction was the virtually complete displacement of the preterit by the periphrastic perfect. By focusing on a single geographical area, this study provides a complement to macrogeographical studies of Upper German preterit loss such as Sapp (2009). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]