The most learned of ancient Latin Christian scholars, whose translation of the Bible into Latin -- commonly called the "Vulgate" -- became the standard authorized version of scripture in Roman Catholic churches for more than 1500 years. Born on the Dalmatian coast near Ljubljana, the capitol of modern Slovenia, Jerome -- whose given name was Eusebius Hieronymus -- was the most widely traveled of all ancient Christian scholars and was personally familiar with virtually every leading churchman of his day except for Augustine.  As a vocal champion of Christian asceticism, Jerome had a profound influence on the development of clerical celibacy & monasticism in the West, as well as upon medieval biblical scholarship.

Having received an excellent classical Latin education at Rome, Jerome became associated with the intellectual circle of Rufinus, who translated many of Origen's works into Latin.  When that group disbanded in 373 CE, Jerome headed East to Antioch & the Syrian desert of Chalcis, where he studied Greek, Hebrew & Syriac (Christian Aramaic) and began to translate Eusebius of Caesarea's Church History. His contacts with Greek church leaders -- both orthodox & heretical -- embroiled him in doctrinal controversies that culminated with his presence at the ecumenical Council of Constantinople (381). In 382 he returned to Rome to become secretary to Pope Damasus, where he began to revise the old Latin versions of the Gospels & the Psalms and to preach the virtues of celibacy. But his preaching raised such a storm of opposition that after the Pope's death (December 384), Jerome returned to the East. Apart from a pilgrimage from Alexandria to the old centers of Christian monasticism at Chenoboskian (near Nag Hammadi) and a few brief side trips to sites in Palestine, Jerome spent the remainder of his life in a monastery he founded at Bethlehem, completing his prodigious project of retranslating the scriptures from Greek into Latin. Aside from his production of the Vulgate, his most significant contribution to later scholarship was his translation of Greek and Coptic works into Latin the original versions of which have since been lost  (e.g., sermons by Origen, Eusebius' book on Hebrew names, & the monastic rule of Pachomius).

In 393 Jerome composed the first Christian Who's Who ("Concerning Illustrious Men") to counter pagan claims that Christian intellectual tradition was inferior to that of the classics. His capsule biographies of the traditional authors of the gospels reveal his personal familiarity with eastern Christian traditions & his own decidedly Roman perspective on church history. 

Concerning Matthew he wrote (chapter 3):

Matthew -- who was also (called) Levi -- was an apostle and former tax-collector. He first composed the gospel of Christ in Hebrew letters and words in Judea for those from the circumcision who had believed. Who later translated (his gospel) into Greek, is not quite certain. Moreover, the Hebrew itself is still held today in the library at Caesarea (Maritima), which the martyr Pamphilus carefully put together. I also was able to make a copy from the Nazarenes, who use this volume in Beroea, a city in Syria. In it, it is to be noted that whenever the evangelist made full use of testimonies from the ancient scriptures -- either on his own or from the Lord Savior -- he did not follow the authority of Seventy translators [i.e., the Greek Septuagint], but of the Hebrew. These are two (examples) of this: "Out of Egypt I have called my Son" (Matt 2:15) and  "For he shall be called a Nazarene" (Matt 2:23).

The fact that Jerome made a personal copy of a version of Matthew in a Semitic language is evidence that this gospel was known in the eastern Mediterranean in languages other than Greek. But whether the language of that text was actually Hebrew or rather Aramaic -- the native language of Semitic Christians in Syria and Palestine -- is debatable, since both were written in the same square script and were closely related in vocabulary. Whether the Greek version of Matthew was a translation of this Semitic text, as Jerome and eastern Christian authors assumed, or vice versa is also a matter of scholarly debate. For citations of this "Hebrew" gospel by Origen, Eusebius and Jerome himself  include material that seems to have been added to the canonical gospel of Matthew. 

Jerome's claim that Matthew did not rely on the standard Greek Septuagint translation of Jewish scripture is of little use for deciding the issue of the original language of this gospel. For while it is true that the citation of Hosea 6:1 in Matthew 2:15 is not based on the Septuagint, there is no clearly identifiable source for Matt 2:23 ("He shall be called a Nazarene") in the Hebrew Bible. Moreover, contrary to Jerome's assertion, the canonical gospel of Matthew is sometimes clearly based on the Greek Septuagint translation of Jewish scripture rather than the Hebrew text; for example, the citation of Isa 7:14 in Matt 1:23 ("Behold a virgin shall conceive...") and Jesus' citations from Deuteronomy in the temptation story (Matt 4:1-11). 

Concerning Mark, Jerome wrote (de viris illus. 8): 

Mark was a disciple and interpreter of Peter. Having been requested by the brethren in Rome, he wrote a brief Gospel just from what he heard Peter relate. When Peter heard this, he approved and published it on his own authority for reading in the churches, just as Clement wrote in the sixth book of his Outlines -- also Papias, the bishop of Hierapolis. Peter also mentioned this Mark in his first letter: "She who is in Babylon chosen together with you, sends you greetings and so does Mark my son" (1 Pet. 5:13) -- signifying Rome figuratively under the name of "Babylon."

Thus, (Mark) took the gospel which he himself composed and proceeded to Egypt. First proclaiming Christ in Alexandria, he founded a church with such teaching and continence in its life-style that it leads all followers of Christ to copy its example. And then, Philo, the most brilliant of the Jews, upon seeing the first church of Alexandria when it was still Jewish, wrote a book about their behavior as if in praise of his own people. And just as Luke relates that the believers of Jerusalem had everything in common, he [Philo] transmitted a memorial of what he saw was done in Alexandria under Mark as teacher. Mark died in the eighth year of Nero [61 CE] and was buried in Alexandria, with Annianus succeeding him.

Although Jerome credits his information about the composition of the gospel of Mark to Clement of Alexandria & Papias, it is uncertain whether he had read these authors himself. For his report simply summarizes the citations of these authors in Eusebius of Caesarea's Church History (2.25.2, 3.39.14-15, & 6.14.5-7), which Jerome himself had translated into Latin. In claiming that Peter personally approved and ordered the gospel of Mark to be read in churches, however, Jerome went beyond what the sources had actually written. For Papias explicitly claimed that Mark wrote after Peter's departure (exodus = death?) and Clement just as explicitly wrote: "And when this matter came to Peter's attention, he neither strongly forbid it, nor urged it on." Jerome's idea that Peter personally authorized the gospel of Mark for the use of other churches was probably based on nothing more than his own view of papal authority. At any rate,  he was clearly inaccurate in ascribing this information to earlier Greek writers.

What Jerome writes about the relationship of the Jewish philosopher and biblical exegete, Philo, to Mark & the Christian church at Alexandria also indicates that the information he conveys as fact needs to be interpreted with caution. Jerome's pilgrimage to Alexandria probably acquainted him with the local tradition that traced that church's founding to Mark & his reading of Origen would have given him ample evidence of the use of Philo's works by Egyptian Christians. But his claim that Philo (ca 15 BCE - 50 CE) --- who was himself a pillar of the Alexandrian Jewish community long before Christianity was introduced there -- described the church of Alexandria under Mark's direction is an unwarranted historical inference, probably based on his misinterpretation of Philo's description of the Egyptian Jewish sect of the Therapeutae.

Jerome's dating of Mark's death also creates problems for the dating of his alleged association with Peter, who according to Roman tradition died in Nero's persecution of Christians for the fire that devastated Rome in 65 CE.

Concerning Luke, Jerome wrote (de viris illus. 7):

Luke (was) a physician from Antioch.  As his writings indicate, he was not ignorant of the Greek speech. As a follower of the apostle Paul and his companion in all his traveling, he wrote a gospel. About him Paul said: "We have sent with him the brother whose praise is in the gospel throughout all the churches" (2 Cor. 8:18); and to the Colossians: "Luke the dearest physician greets you" (4:14), and to Timothy: "Luke alone is with me" (2 Tim. 4:11)...  Some suspect that whenever Paul says "according to my gospel" in his letters (e.g., Rom 16:23), he means Luke's volume and that Luke was taught the gospel not only by Paul, who had not been with the Lord in the flesh, but also by the other apostles. 

As with his descriptions of Matthew & Mark, Jerome here amplifies standard Greek Orthodox tradition identifying a separate apostolic source for the gospel of Luke. But Jerome was the first writer to recognize a historical problem with the fact that Paul -- the reputed source of Luke's information -- was not himself an eye-witness to the events Luke describes. Therefore, he introduced the suggestion that the information in the gospel of Luke was supplied by anonymous "other apostles."

It is surprising that although Jerome himself translated the gospels from Greek into Latin, he apparently never suspected that there was a direct literary relationship between the synoptic gospels. Credit for this insight must go, not to this greatest of patristic biblical scholars, but to his younger contemporary, Augustine of Hippo.

Other on-line resources

• De Viris Illustribus (On Illustrious Men) - the complete English translation of Jerome's Who's Who in early Christianity from The Fathers of the Church (posted by New Advent).

• St. Jerome - Vol 6 in Philip Schaff's Nicene and Post-Nicene Fathers, second series, containing Jerome's most important letters, treatises & prefaces to works he translated (posted by Christian Classics Ethereal Library).

• St. Jerome - Louis Saltet's article on the Latin father in New Advent's electronic edition of the 1910 Catholic Encyclopedia.