This thesis details the influence of Pietism on the development of Psychiatry in eighteenth-century Prussia. Although Pietism’s influence on society, culture, medicine, and science has been studied, its explicit impact on psychiatry’s development has yet to uncovered. There is a deeper connection between psychiatry as a medical discipline and the culturally and religiously informed society in which it was developed. Institutionalised Pietism developed in the late seventeenth century institutions of Halle an der Saale (hereafter known as the Glaucha Anstalten). August Herman Francke (1663-1727) founded the Glaucha Anstalten in 1695. He championed a deeply personal, introspective, and anthropologically holistic understanding of the human mind, body, and soul. The medical institutions of the Glaucha Anstalten (among them a pharmaceutical laboratory and hospitals) co-operated with the medical faculty of the nearby University of Halle, the so-called Fridericiana. They medical faculty co-operated with the Glaucha Anstalten, providing staff and lecturers to administer the institutions. Likewise, the Pietist movement organised out of the Glaucha Anstalten, exerted influence and organisational support, thereby propagating its ideals throughout Prussia. Therefore, we propose that Pietist Christian anthropology influenced medicine at the university of Halle and on the development of psychiatry in Prussia as a distinct discipline in eighteenth century Prussia.