Were The Disciples Martyed?

Were The Disciples Martyred?
When arguing on the reliability of the New Testament, a common point made is that the apostles died for their faith; however, is there any evidence of this?

According to Clement who was writing in the late first century: "Let us set before our eyes the illustrious apostles. Peter, through unrighteous envy, endured not one or two, but numerous labours; and when he had at length suffered martyrdom, departed to the place of glory due to him. Owing to envy, Paul also obtained the reward of patient endurance, after being seven times thrown into captivity, compelled to flee, and stoned. After preaching both in the east and west, he gained the illustrious reputation due to his faith, having taught righteousness to the whole world, and come to the extreme limit of the west, and suffered martyrdom under the prefects," (Letter to The Corinthians, V). According to Clement, both Peter and Paul were martyred. 

Ignatius also writes: "You are initiated into the mysteries of the Gospel with Paul, the holy, the martyred, the deservedly most happy, at whose feet may I be found, when I shall attain to God; who in all his Epistles makes mention of you in Christ Jesus," (The Epistle of Ignatius to the Ephesians, Chapter 12: Praise of the Ephesians). 

In a text attributed to Hippolytus, it is written: "Nicanor died when Stephen was martyred ... But the one being induced to return to the Lord by Peter's instrumentality, and the other by Paul's, they were honoured to preach that Gospel on account of which they also suffered martyrdom, the one being burned, and the other being crucified on an olive tree ... Trophimus, who was martyred along with Paul," (On the Apostles and Disciples, On the Seventy Disciples).

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Translated by J.H. MacMahon. From Ante-Nicene Fathers, Vol. 5. Edited by Alexander Roberts, James Donaldson, and A. Cleveland Coxe. (Buffalo, NY: Christian Literature Publishing Co., 1886.) Revised and edited for New Advent by Kevin Knight. <http://www.newadvent.org/fathers/0524.htm>.

Translated by John Keith. From Ante-Nicene Fathers, Vol. 9. Edited by Allan Menzies. (Buffalo, NY: Christian Literature Publishing Co., 1896.) Revised and edited for New Advent by Kevin Knight. <http://www.newadvent.org/fathers/1010.htm>.