Companion and Disciple of Augustine
Possidius was one of the clergy formed in Augustine's monastery at Hippo, and the two men maintained what has been described as an unbroken friendship of roughly forty years. This close association shaped Possidius's episcopate: when raised to the see of Calama, he modeled his own ministry on Augustine's, establishing a monastery there as his master had done at Hippo.
His nearness to Augustine extended to the very end of the elder bishop's life. Having fled to Hippo before the advancing Vandals, Possidius was present when Augustine died in 430.
Controversies and Church Councils
Possidius was drawn repeatedly into the conflicts that marked the African Church of his time. In 404 he was assaulted by Donatist extremists, and in 408 he narrowly survived a pagan-incited riot at Calama. In 409 he was sent to Italy to seek imperial protection against the Donatists.
In 411 he served as one of seven bishops representing the Catholic party at the Conference of Carthage, the great collatio convened to address the Donatist schism. In 416 he assisted at the Council of Milevum and co-signed a synodal letter to Pope Innocent I opposing the teaching of Pelagius.
Writings
Possidius is the author of the Vita Sancti Augustini, a biography of Augustine composed before the fall of Carthage in 439. As the first life of Augustine, written by one who knew him intimately, it has been included in editions of Augustine's works.
He also compiled the Indiculus, an index or catalogue of Augustine's writings, preserved in the Benedictine edition and in the final volume of Migne's edition of Augustine. Modern critical editions of Possidius's work include those of Weiskotten (2008) and Kuhn (2023).
Veneration
Possidius is commemorated on May 16. Roman Catholic devotion to him was confirmed by Pope Clement X on 19 August 1672, together with Alypius of Thagaste.
His veneration is noted in general reference sources, but he does not appear in the Orthodox Church in America's calendar for May 16, and OrthodoxWiki carries no article on him; the sources on his life are principally historical rather than liturgical.