Two disputes dominated Innocent I's dealings beyond Italy. The first came from the East. John Chrysostom, the ascetic preacher made archbishop of Constantinople, was deposed and exiled after the Synod of the Oak in 403 in a proceeding driven by his enemies at court and by Theophilus of Alexandria. Innocent refused to recognize the deposition, wrote in Chrysostom's defence, sent a legation that was turned back, and broke communion with Constantinople, Alexandria and Antioch over the affair. Chrysostom died in exile in 407, and the breach was healed only when his name was restored to the diptychs years afterwards.
The second came from Africa. Pelagius and his follower Caelestius taught that human beings can choose the good without a prior and interior gift of grace, a position Augustine read as emptying baptism and the cross of their necessity. African councils at Carthage and Milevis condemned the two in 416 and wrote to Rome asking for confirmation. Innocent replied in January 417 upholding the condemnations, and Augustine, preaching at Carthage that autumn, told his congregation that two councils had written to the apostolic see, the replies had come back, and the case was finished.
Augustine's actual words were causa finita est, the case is finished. The familiar tag Roma locuta est, causa finita est, Rome has spoken, the case is closed, is a later condensation that does not appear in his sermon, and it carries a stronger sense of Roman finality than his argument allows: Augustine was pointing to the agreement of councils and see together. The distinction matters, because the sentence has been quoted on both sides of the question of papal authority for fifteen hundred years. Innocent died within months, and his successor Zosimus promptly reopened the Pelagian case.