Saint Justus of Sipellum is a Hosian monastic saint and the founder of the Order of Justine Friars, the first order in the Aurorian tradition of Hosian monasticism. Born a wealthy Selucian nobleman from the town of Sipellum, he abandoned his studies in Auroria for life as a hermit, living in a cave near Mons Cassii. His lifestyle attracted followers who joined him there, forming the foundation of the first Justine order. St. Justus and his brothers left the caves to found the first Justine monastery in 605, with Justus serving as abbot, having authored the Rule of St. Justus to regulate the life of the monastic community.