Nothing is known of Ignatius' life apart from what may be inferred internally from his letters, except from late spurious traditions. It is said Ignatius converted to Christianity at a young age. Tradition identifies Ignatius, along with his friend Polycarp, as disciples of John the Apostle. Later in his life, Ignatius was chosen to serve as Bishop of Antioch; the fourth-century Church historian Eusebius writes that Ignatius succeeded Evodius. Theodoret of Cyrrhus claimed that St. Peter himself left directions that Ignatius be appointed to the episcopal see of Antioch. Ignatius called himself Theophorus (God Bearer). A tradition arose that he was one of the children whom Jesus took in his arms and blessed.
Ignatius' own writings mention his arrest by the authorities and travel to Rome to face trial:
From Syria even to Rome I fight with wild beasts, by land and sea, by night and by day, being bound amidst ten leopards, even a company of soldiers, who only grow worse when they are kindly treated.
Ignatius' transfer to Rome is regarded by scholars as unusual, since those persecuted as Christians would be expected to be punished locally. If he were a Roman citizen, he could have appealed to the emperor, but then would usually have been beheaded rather than tortured. Allen Brent has suggested that Ignatius was involved in conflict with other Christians and was executed for the capital crime of disturbing the peace.
During the journey to Rome, Ignatius and his entourage of soldiers made a number of stops in Asia Minor. Along the route Ignatius wrote six letters to the churches in the region and one to a fellow bishop, Polycarp, bishop of Smyrna. In his Chronicle, Eusebius gives the date of Ignatius's death as AA 2124 (2124 years after Abraham), i.e. the 11th year of Trajan's reign, AD 108. Ignatius himself wrote that he would be thrown to the beasts, and in the fourth century Eusebius reports tradition that this came to pass, which is then repeated by Jerome, who is the first to explicitly mention "Lions". John Chrysostom is the first to allude to the Colosseum as the place of Ignatius' martyrdom. Contemporary scholars are not clear that any of these authors had sources other than Ignatius own writings.