St. Chromatius was born in the late fourth century in the city of Aquileia in eastern Italy. His biography tells us that Chromatius lived with his widowed mother, his brother, and his unmarried sisters. Instead of continuing to live with his mother and sisters as their financial guardian, however, Chromatius was ordained a priest around the year 381. Shortly thereafter, Chromatius participated in the small Synod of Aquileia, which condemned Arius as a heretic and worked to establish an orthodox Christology, against Arius. This synod was organized by St. Ambrose, a distinguished theologian, who became a friend, mentor, and correspondent of Chromatius. In 388, Chromatius was elected bishop of Aquileia. 

Although Chromatius himself is no longer a very well-known name, he was friends with many influential and famous theologians. He baptized Rufinus and became something of a mentor to him. Rufinus and St. Jerome disagreed over Origen's theology and style of exegeting scriptures. Chromatius took it upon himself to mediate the dispute of these two friends of his. Chromatius exerted his influence on his young mentee, Rufinus, and exhorted him to cease arguing with Jerome and instead turn his intellectual abilities to translate the great Church historian Eusebius' Ecclesiastical History out of Greek and into Latin. Chromatius was a dear friend of the great St. Jerome, who translated the Bible into Latin. In fact, Chromatius is responsible for helping to finance Jerome's daring venture. In addition to his active correspondences with Ambrose, Rufinus, and Jerome, he also corresponded with the  Church historian Eusebius.

Chromatius was also a prolific scriptural commentator and exegete in his own right. Part of his commentaries on Matthew's Gospel still survive today, including a beautiful homily on the beatitudes. 

Another one of Chromatius' correspondents was the famous preacher St. John Chrysostom, priest of Antioch and then bishop of Constantinople. John Chrysostom criticized the royal family for their excess and their hypocritical practice of Christianity. Emperor Honorius promptly exiled John Chrysostom: a sentence which led finally to John Chrysostom's death. Chromatius interceded with Emperor Honorius on John Chrysostom's behalf, asking him to relieve him from his death march of exile. His pleas went unheeded, but provide yet another example of Chromatius putting his pastoral care and intellectual acumen at the service of Christian friendship, of building up the body of Christ through care for his friends and colleagues.

Chromatius, having thoroughly spent himself serving the Church that he loved so dearly, died on December 2 in the year 406 or 407. 

St. Chromatius, faithful friend, who encouraged great saints to use their gifts for Christ—pray for us!