Saint Agathangelus was a disciple of Saint Clement (see below).
Sts Clement and Agathangelus were denounced as Christians and sent to the governor Agrippina, who subjected them to such inhuman torments, that even the pagan on-lookers felt pity for the martyrs and they began to pelt the torturers with stones.
Having been set free, the saints healed an inhabitant of the city through the laying on of hands and they baptized and instructed people, thronging to them in multitudes. Arrested again on orders of Maximian, they were sent home to Ancyra, where the ruler Cyrenius had them tortured. Then they were sent to the city of Amasea to the proconsul Dometius, known for his great cruelty.
In Amasea, the martyrs were thrown into hot lime. They spent a whole day in it and remained unharmed. They flayed them, beat them with iron rods, set them on red-hot beds, and poured sulfur on their bodies. All this failed to harm the saints, and they were sent to Tarsus for new tortures. In the wilderness along the way Saint Clement had a revelation that he would suffer a total of twenty-eight years for Christ. Then having endured a multitude of tortures, the saints were locked up in prison.
Saint Agathangelus was beheaded with the sword on November 5. The Christians of Ancyra freed Saint Clement from prison and took him to a cave church. There, after celebrating Liturgy, the saint announced to the faithful the impending end of the persecution and his own martyrdom. On January 23, the holy hierarch was killed by soldiers from the city, who stormed the church. The saint was beheaded as he stood before the altar and offered the Bloodless Sacrifice. Two deacons, Christopher and Chariton, were beheaded with him, but no one else was harmed.