Antipopes and the law: jurisdiction & legal practice during the schisms of the twelfth century'.

The twelfth-century saw an increase in the practical realisation of papal authority in Latin Christendom. By the pontificate of Innocent III, the popes could both claim and enact extensive powers over individuals' lives, including the ability to decide the validity of oaths and marriages, and were engaged in high-level political disputes. All this was founded on a legal supremacy, and the papal role as highest judge in the Church. But the story of the centralisation of papal power comes with its complexities, and this paper will investigate one: the case of anti-popes, those elected pope in a contested election but who, regardless of whether their claim was stronger, lost the resulting schism and their claim to legitimacy. The twelfth century saw two major schisms. Looking particularly at the 1159-77/78 Alexandrine Schism, where Alexander III faced three consecutive (anti-)popes backed by Emperor Frederick Barbarossa, this paper will piece together how those (anti-)popes conceived, understood, and enacted their legal role in the church while they were pope, something mostly overlooked amidst political questions and the damnatio memorie enacted by Alexander and his successors. Supported by the emperor and recognised in his lands, this paper will use specific cases to investigate when, how, and where the anti-popes exercised their legal power and jurisdiction, nuancing our understanding of the practice of papal law in the twelfth century.