A brief summary of the lives, works and martyrdoms of each of the 12 Apostles, including St. Paul the Apostle: New Advent Entries on each of the Apostles are also good and can be consulted. Fr. Butler's entries for their feast days are excellent with detailed references.
1: St. Peter the Apostle, and St. Paul: Sts. Peter and St. Paul were martyred in Rome under the emperor Nero on the same day around A.D. 67. St. Peter had been Bishop of Rome - and had governed Antioch for about 7 before that - for around 25 years and had written the two Petrine epistles. St. Paul had written the 14 glorious epistles that we have in our Bible, and was a great witness to the Truth of the Risen Christ. A former Rabbi - who studied under Rabbi Gamaliel I, grandson of Hillel, a contemporary of Christ, who himself later converted, as St. Luke implies and St. Clement explicitly relates - who was at once a fierce persecutor of Christ, the 180 degree turn he experienced and his heroic labors, sufferings, stripes, persecution and final witness for the Gospel in his blood can only be explained by his encounter with the Risen Christ, on the Road to Damascus, as he gave us sworn eyewitness testimony. St. Peter, Prince and Head of the Apostles, who already commends St. Paul's epistles and labors so highly in his last epistle, stamps his work and life with full Pontifical approval, and gave his own life in heroic martyrdom together with St. Paul in Rome. Their feast day is on 29th June (St. Paul 30th in Fr.B)
St. Peter:
https://www.bartleby.com/210/6/291.htmlSt. Paul:
https://www.bartleby.com/210/6/301.htmlThe ridiculous assertions of some later modernists that "Paul invented Christianity, other Apostles rejected him" is totally refuted by this.
2: St. James the Great, Apostle of Spain: St. James the Great, Apostle of Spain, who heralded the impending triumph of the Catholic Faith in all Europe, as Sts. Peter and St. Paul had done in Rome, Mother Church and Teacher of the Whole World, was the first of all the holy Apostles to be boldly and courageously martyred out of unstoppable and indefatigable zeal for the glory of the Risen Christ. The very fact that St. James labored so much to go to Spain and then suffered death for Christ is a standing rebuke to the silly secularism and indifferentism of our time, and an invitation to come to Christ and experience His Love and Power as True God. St. James would not do this for a man who he had ascertained dead. St. James' labors in Spain, as Fr. Butler summarizes, "That he preached there, is constantly affirmed by the Tradition of that Church, mentioned by St. Isidore, the Breviary of Toledo, the Arabic books of Anastasius patriarch of Antioch, concerning the Passions of the martyrs and others. Cuper the Bollandist, 4 traces this tradition very high, and confirms it from St. Jerom, 5 St. Isidore, the ancient Spanish office, &c., and from many corroborating circumstances. St. Epiphanius says, that St. James always lived a bachelor, in much temperance and mortification, never eating flesh nor fish; that he wore only one coat, and a linen cloak, and that he was holy and exemplary in all manner of conversation. He was the first among the apostles who had the honour to follow his divine master by martyrdom, which he suffered at Jerusalem, whither he was returned, in the eleventh year after our Lord’s ascension."
St. Luke itself records his martyrdom in Acts, under Herod Agrippa, about A.D. 43. His martyred blood was the seed of the Church.
His feast day is on July 25th. Fr. Butler's entry on St. James is here:
https://www.bartleby.com/210/7/251.html3: St. James the Just, Bishop of Jerusalem: A cousin brother of Our Lord and son of Alpheus, this Apostle is mentioned by Josephus, and was universally styled as "the Just" in Jerusalem, for his perfect imitation of Christ, and manifestly holy life, even by non-believing Jews. St. James is an incredible eyewitness testimony to the fact of the Risen Christ right in the very hometown of his death, whom no one was able to answer. After a heroic life of about 30 years and daily martyrdom for love of Christ, St. James was put to such a cruel death, that non-believers themselves, said that almost certainly Jerusalem would now fall, for killing such a just man. That came about in 70 A.D.
His feast in Fr. Butler's entry is on May 1st. The entry here:
https://www.bartleby.com/210/5/012.html Account of his martyrdom below.
"Wherefore, during this interval, Ananus, the high-priest, son of the famous Annas mentioned in the gospels, having assembled the Sanhedrim, or great council of the Jews, summoned St. James and others before it. Josephus, the Jewish historian, says, 23 that St. James was accused of violating the laws, and delivered to the people to be stoned to death. And Hegesippus adds, 24 that they carried him up to the battlements of the temple, and would have compelled him from thence to make a public renunciation of his faith in Christ, with this further view, thereby to undeceive, as they termed it, those among the people who had embraced Christianity. But St. James took that opportunity to declare his belief in Jesus Christ after the most solemn and public manner. For he cried out aloud from the battlements, in the hearing of a great multitude, which was then at Jerusalem on account of the passover, that Jesus, the Son of man, was seated at the right hand of the Sovereign Majesty, and would come in the clouds of heaven to judge the world. The Scribes and Pharisees, enraged at this testimony in behalf of Jesus, cried out: “The just man also hath erred.” And going up to the battlements, they threw him headlong down to the ground, saying: “He must be stoned.” St. James, though very much bruised by his fall, had strength enough to get upon his knees, and in this posture, lifting up his eyes to heaven, he begged of God to pardon his murderers, seeing that they knew not what they did. The rabble below received him with showers of stones, and at last a fuller gave him a blow on the head with his club, such as is used in dressing of cloths, after which he presently expired. This happened on the festival of the Pasch, the 10th of April, in the year of Christ 62, the seventh of Nero. He was buried near the temple, in the place in which he was martyred, where a small column was erected. Such was the reputation of his sanctity, that the Jews attributed to his death the destruction of Jerusalem, as we read in St. Jerom, 25 Origen, 26 and Eusebius, 27 who assure us that Josephus himself declared it in the genuine editions of his history. Ananus put others to death for the same cause, but was threatened for this very fact by Albinus, and deposed from the high-priesthood by Agrippa."
The rest later. New Advent or the Bartleby site with Fr. Butler's entries can be consulted by any inquirer. We know of Plato and Aristotle in part because of their influence on their disciples. In the same way, we know Christ is Risen, because He made His Apostles who up till then had been wavering, weak and scared great and holy men who were heroes, Saints, Martyrs, and World-Conquerors.
