The first Pope John was born in Tuscany, and served as an archdeacon for many years before being selected as pope in 523, succeeding St. Pope Hormisdas.
During Pope John’s reign, Italy was ruled by King Theodoric, an Ostrogoth. Like many of his tribesmen, the king believed the Arian heresy that Christ was a created being rather than the Second Person of the Holy Trinity.
In 523, Byzantine Emperor Justin I ordered Arian clergy to surrender their churches into orthodox Catholic hands. In the West, this angered Theodoric, who responded by trying to use the pope’s authority for his own means.
Although Pope John believed in the true nature of Christ, Theodoric expected him to intercede with Justin on behalf of the Arian heretics. John’s refusal would eventually lead to his death.
John traveled to Constantinople, where he was honored as St. Peter’s successor by Emperor Justin and the Church’s legitimate Eastern patriarchs. John crowned the emperor and celebrated the Easter liturgy at the Hagia Sophia Church in April 526.
Theodoric was furious when he learned that John had not supported the Arians during his visit to Constantinople. The gothic king had already killed John’s friend Boethius (honored by the Church as St. Severinus Boethius).
The pope, exhausted from his extensive travels, was imprisoned in Ravenna and deprived of food. He died around May 18, and the date became his feast day.