Saint Irenaeus was a prominent early Christian theologian and writer, who was renowned for his contributions to the development of Christian theology and for his defense of orthodox Christianity against heretical teachings. Over the years, he has been referred to by a number of different names and titles, each designed to highlight a different aspect of his life and ministry. Some synonyms for Saint Irenaeus include "Irenaeus of Lyon," "Bishop Irenaeus," "Irenaeus of Gaul," "Father of the Church," and "Defender of Orthodoxy." Each of these titles speaks to the significant impact that Saint Irenaeus had on the early Christian church, and his lasting legacy as a key figure in the theological development of Christianity.