Alexander in the Bible Encyclopedia - ISBE

al-eg-zan'-der (Alexandros, literal meaning "defender of men." This word occurs five times in the New Testament, Mk 15:21; Acts 4:6; 19:33; 1 Tim 1:19,20; 2 Tim 4:14): It is not certain whether the third, fourth and fifth of these passages refer to the same man. 1. A Son of Simon of Cyrene: The first of these Alexanders is referred to in the passage in Mk, where he is said to have been one of the sons of Simon of Cyrene, the man who carried the cross of Christ. Alexander therefore may have been a North African by birth. Matthew, Mark, and Luke all record the fact, with varying detail, that Simon happened to be passing at the time when Christ was being led out of the city, to be crucified on Calvary. Mark alone tells that Simon was the father of Alexander and Rufus. From this statement of the evangelist, it is apparent that at the time the Second Gospel was written, Alexander and Rufus were Christians, and that they were well known in the Christian community. Mark takes it for granted that the first readers of his Gospel will at once understand whom he means. There is no other mention of Alexander in the New Testament, but it is usually thought that his brother Rufus is the person mentioned by Paul in Rom 16:13, "Salute Rufus the chosen in the Lord, and his mother and mine." If this identification is correct, then it follows, not only that the sons of Simon were Christians, but that his wife also was a Christian, and that they had all continued faithful to Christ for many years. It would also follow that the households were among the intimate friends of Paul, so much so that the mother of the family is affectionately addressed by him as "Rufus' mother and mine." The meaning of this is, that in time past this lady had treated Paul with the tender care which a mother feels and shows to her own son...

Link: https://bible-history.com/isbe/A/ALEXANDER/