Sixtus I was a Roman bishop of Greek descent who served as Pope from approximately 117 or 119 until his death around 126 or 128. Succeeding Alexander I, he led the early Church during the Roman Empire. He is recognized as a saint in several Christian traditions, including the Catholic, Orthodox, and Anglican churches. His tenure, which lasted roughly ten years, was marked by the establishment of specific liturgical and administrative rules that helped organize the growing ecclesiastical structure of the time.