Who knew that a couple of future SAINTS and DOCTORS of the Church made for such an odd couple?  Jerome and Augustine were famous rivals, especially when it came to his translation project.  Augustine thought the Greek Septuagint was inspired and thought Jerome was wasting his time.  Jerome, in his acerbic and caustic manner, returned heat in several letters between the two.  The letters of St. Jerome were originally translated in 1956.  His "hot takes" on the hot button issues of the day - and his "frenemy" St. Augustine - make for great insight into such a hot-headed, but brilliant saint.
 

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"Ignorance of the Scriptures is ignorance of Christ."
St. Jerome

Jerome (c. 342-347 – 30 September 420) was a Latin priest, confessor, theologian, and historian; he is commonly known as Saint Jerome.

Jerome was born at Stridon, a village near Emona on the border of Dalmatia and Pannonia.He is best known for his translation of most of the Bible into Latin (the translation that became known as the Vulgate) and his commentaries on the Gospels. His list of writings is extensive. 

The protégé of Pope Damasus I who died in December of 384, Jerome was known for his teachings on Christian moral life, especially to those living in cosmopolitan centers such as Rome. In many cases, he focused his attention on the lives of women and identified how a woman devoted to Jesus should live her life. This focus stemmed from his close patron relationships with several prominent female ascetics who were members of affluent senatorial families. 

Jerome is recognised as a saint and Doctor of the Church by the Catholic Church.  His feast day is 30 September.
Source: https://en.wikipedia.org/wiki/Jerome

To call this a "greatest work" is an understatement to say the least.  For most of Roman society, the Greek translation of the Old Testament that came from the Septuagint had become more and more inaccessible as the old Greek influence waned in the Empire.  But instead of making his translation from the Greek, he went against conventional wisdom and decided to translate directly from the original Hebrew.  He aligned himself with mainstream Rabbinical Judaism, which believed the Septuagint had numerous translation issues (going from Hebrew to Greek), and so rejected it.  Although there were other Latin translations from the Greek, St. Jerome stuck to his guns and worked painstakingly for twenty-three years (!) completing the project.  

Today we know his translation more commonly as the "Latin Vulgate".  And the Latin Vulgate was faithfully translated into English as what we know as the "Douay-Rheims" bible. 

In 1943, Pope Pius XII determined that a new translation of the Old Testament should be undertaken, stemming from the orginal Hebrew instead of the Greek (the New Testament was originally in Greek, so there were only general corrections to the Vulgate translation).
This translation, in English, came to be known as the "New American Bible" (NAB) which we use in Catholic liturgy today.  
 

Latin Vulgate (Douay-Rheims English) 

"... You tell me that I have given a wrong translation of some word in Jonah, and that a worthy bishop narrowly escaped losing his charge through the clamorous tumult of his people, which was caused by the different rendering of this one word. At the same time, you withhold from me what the word was which I have mistranslated; thus taking away the possibility of my saying anything in my own vindication, lest my reply should be fatal to your objection."

St. Jerome writing to St. Augustine