In May of 1591, Catherine McGillis, a resident of the royal burgh of Haddington, became the subject of a formal legal proceeding regarding the practice of witchcraft. The records of the Justiciary Court, indexed under case C/EGD/102, identify Catherine as the primary focus of an inquiry that initiated on the 8th of May. At this time, Haddington was a center of administrative activity where such accusations were handled with the solemnity and rigor characteristic of late sixteenth-century Scottish judicial practice.
Following the initial registration of the case, the matter proceeded to the formal trial stage, recorded under reference T/LA/967. This transition from inquiry to trial reflects the standard legal processes of the era, wherein evidence—often comprising testimonies of neighbors or local officials—was brought before the court to determine the validity of the charges. The record for Catherine serves as a documented instance of the broader patterns of prosecution that defined this period of Scottish history, marking her involvement in a legal system tasked with navigating the intersections of community reputation, religious conviction, and the law.