The Order of Justine Friars (also known as the Justine Order or Order of St. Justus) is an Aurorian Hosian religious order with branches in both main Patriarchal Churches, though the original Order of Justine Friars belongs to the Aurorian Patriarchal Church, having rejoined the Selucian Patriarchal Church shortly after it resurfaced. As the oldest monastic order in Hosianism, it traces its roots back by communities established and operating under a rule formulated by St. Justus of Sipellum, who is considered to have established the Aurorian tradition of monasticism (as opposed to the earlier and more ascetic Augustan Hosian monasticism).