Fourteen of the twenty-seven books in the New Testament have traditionally been attributed to Paul. Seven of the epistles are undisputed by scholars as being authentic, with varying degrees of argument about the remainder.
It has been popularly assumed that Saul"s name was changed when he converted from Judaism to Christianity, but that is not the case. His Jewish name was "Saul" (Hebrew: Modern Sha"ul, "asked for, prayed for, borrowed"), perhaps after the biblical King Saul, a fellow Benjamite and the first king of Israel. According to the Book of Acts, he inherited Roman citizenship from his father. As a Roman citizen, he also bore the Latin name of "Paul" — in biblical Greek: Paulos, and in Latin: Paulus. [Acts 16:37] It was quite usual for the Jews of that time to have two names, one Hebrew, the other Latin or Greek.
Paul referred to himself as being "of the stock of Israel, of the tribe of Benjamin, a Hebrew of the Hebrews; as touching the law, a Pharisee." [Phil. 3:5]
Eusebius of Caesarea in his Church History (320 AD) testifies that Paul was beheaded in Rome and Peter crucified. He wrote that the tombs of these two apostles, with their inscriptions, were extant in his time; and quotes as his authority a holy man of the name of Caius.
Paul"s influence on Christian thinking arguably has been more significant than any other New Testament author.
A Roman Catholic liturgical solemnity of Peter and Paul, celebrated on June 29, commemorates his martyrdom, and reflects a tradition (preserved by Eusebius) that Peter and Paul were martyred at the same time. Source Wikipedia.