[2] In the second half of the fourth century, Byzantius, the Roman senator, and Pammachius, his son, fashioned their house on the Cælian Hill into a Christian basilica.

He was probably among the viri genere optimi religione præclari, who in 390 denounced Jovinian to Pope Siricius.

After her funeral, Pammachius gave substantial alms to the poor for the repose of her soul.

In 398, with another friend, Fabiola, he built at Porto, at the mouth of the Tiber opposite Ostia, the Xenodochium of Pammachius, a guest-house for pilgrims.

In 401 Pammachius was thanked by Augustine of Hippo for a letter he wrote to the people of Numidia, where he owned property, exhorting them to abandon the Donatist schism.