Saint Stephen the First Martyr (a.k.a. the Protomartyr of the Church):

In A.D. 33, Stephen was chosen by the apostles and ordained to be a deacon of the nascent Church at Jerusalem. He was subsequently arrested by the Jewish Sanhedrin for heresy. His “defense speech” is in fact a resounding defense of the truth of that Jesus of Nazareth was, in fact God’s promised Messiah who had been arrested by this same Sanhedrin, who had manipulated Pontius Pilate into trying and executing Jesus for a treason he had not committed. And that God had resurrected his messiah from the death and was now raising up a church of loyal followers who were now spreading the truth in Jerusalem and the surrounding areas. This testimony aroused the Jews of the Sanhedrin, severely. The Chief Priest and the Sanhedrin then declared Stephen guilty of blasphemy and heresy and took him outside the city where they stoned him to death (making him the church’s first martyr; i.e. the protomartyr of the church). Saul of Tarsus observed this event and he was impressed by Stephen’s courage (see chapter 7 of the Acts of the Apostles).
Stephen’s martyrdom was immediately followed by a great persecution against the church in Jerusalem, which was stimulated by the Sanhedrin and led by Saul of Tarsus, the Pharisee!