Here's the skinny on St. Peter Chrysologus:
St. Peter Chrysologus (ca. 406-450) was a fifth-century bishop and teacher; he was given the nickname "Chrysologus" ("golden speech") because of his eloquence, but aside from a collection of homilies, none of his writings have survived. At a young age Peter was appointed bishop of the city of Ravenna in Italy, where he worked tirelessly to overcome Church abuses and religious controversies. Eutyches, a heretical bishop who had been deposed for denying the humanity of Christ, sought assistance from a number of other bishops, including Peter.
The saint instead upheld the Church’s official teaching and the authority of the pope, and urged Eutyches to reconcile himself with the Church. Peter devoted himself to his writings and to instructing his people through his sermons, which were short, simple, and designed to relate the teachings of the gospel to daily life. St. Peter Chrysologus died around 450, and in 1729 he was declared a Doctor (an eminent and reliable teacher) of the Church.