Our celebration today honors the memory of two saints who were intimate friends of Saint Augustine and members of his religious community. Like him they were also called to ministry as bishops in North Africa and served the Church well especially in helping to reveal the fallacies of unorthodox teachings at the time. Their love for religious life according to the inspiration of Augustine helped to spread its influence in North Africa.

Possidius, the first biographer of Augustine, was born in northern Africa, and became a member of Augustine's first monastic community in Hippo, along with Saint Alypius. He was named Bishop of Calama (Numidia), where he faced opposition from the Donatists. Possidius narrowly escaped death on one occasion when Donatist extremists set fire to a house where he was visiting . Twice he went to Italy to defend the rights of the African Church. He was present at the Councils in Carthage in 403 and 407, and was chosen along with Alypius and Augustine to represent the Catholic Bishops at the famous meeting with the Donatists in Carthage in 411. He also took part in the Councils of Milevi (416) and Carthage (419) which treated of the Pelagian heresy. When Calama was conquered by Vandal invaders in 429, Possidius took refuge with Augustine inside the walls of Hippo and was with Augustine at the latter's death in 430. Possidius returned to Calama, but in 437 was exiled by King Hunmeric, who suppressed Christianity and forced Arianism on the territories that he conquered. During this time of exile, Possidius completed his famous book, The Life of Augustine. He died in exile around the year 437.

The Order has celebrated the feasts of Alypius and Possidius since 1671. Clement X confirmed devotion to them on August 19, 1672. The memory of these two saints is closely tied, both as monks and bishops, to that of Saint Augustine. They are, in fact, the two greatest representatives of his monastic legacy. However, it is not for this reason alone that history remembers them. They were dedicated Christians, religious and shepherds of the Church in their own right.