One of the most interesting passages in Mark’s Passion Narrative, from a historiographical perspective, is Mark 15:21:
A certain man from Cyrene, Simon, the father of Alexander and Rufus, was passing by on his way in from the country and they forced him to carry the cross.
First let us compare the passage to its parallels in the Gospels of Luke and Matthew (it does not appear at all in the Gospel of John).
As they led him away, they seized a man, Simon of Cyrene, who was coming from the country, and they laid the cross on him, and made him carry it behind Jesus.
As they went out, they came upon a man from Cyrene named Simon; they compelled this man to carry his cross.
Matthew and Luke retain the reference to Simon as well as describe him as being from Cyrene, but drop the reference to Cyrene being “the father of Alexander and Rufus.”
It is notable that Mark identifies Simon by name. This is rare for Mark unless the author is referring to the disciples and some family or notable persons such as Pilate. Usually, the people with whom Jesus interacts are more generally referenced: "a man in their synagogue who was possessed by an evil spirit,” “Simon's mother-in-law,” “A man with leprosy,” “Some men came, bringing to him a paralytic,” “a man with a shriveled hand,” "Jesus' mother and brothers,” "a man with an evil spirit came from the tombs to meet him,” “a woman whose little daughter was possessed by an evil spirit,” "a man who was deaf and could hardly talk,” "some people brought a blind man,” “A man in the crowd,” “a man ran up to him and fell on his knees before him,” “One of the teachers of the law,” and “the centurion.” Many other times Mark is just as vague about Jesus’ interaction with groups, such as “teachers of the law” or “Pharisees” and “chief priests.” In the aforementioned examples, Jesus interacts with the person or group at least as much as with Simon of Cyrene, if not more so.
There are a few notable exceptions other than Simon of Cyrene, such as “a blind man, Bartimaeus (that is, the Son of Timaeus)” and “reclining at the table in the home of a man known as Simon the Leper.” But the case is nevertheless made that Mark only sparingly refers to what we might call incidental or supporting characters in his narrative. Simon, as well as Bartimaeus and Simon the Leper, appear to carry an importance to the tradition that exceeds the part they play in the narrative itself.
The cross-carrying Simon, of course, is not identified by his name alone. There are other Simons in Mark’s text: Simon called Peter, and Simon the Zealot, both of whom are disciples of Jesus. As a result, aside from any other reason to do so, Mark had cause to distinguish Simon the cross-carrier from the other Simons in his narrative. The identification of Simon as being “of Cyrene” adequately fulfills this purpose. Mark elsewhere refers to a person’s place of origin to distinguish the person from others of the same name, such as with “Simon the Cananite,” and “Joseph of Arimathea.” Elsewhere Mark identifies an otherwise unidentified woman by her place of origin: “The woman was a Greek, born in Syrian Phoenicia.” This kind of identification is common practice in other ancient writings, including the other Gospels.
As Matthew and Luke’s treatment of the passage suggests, however, Mark’s reference to Simon being “of Cyrene” is sufficient to identify and distinguish Simon the cross-carrier. Cyrene was a Greek colony -- a port city -- in what is modern day Libya. There was a Jewish community in Cyrene, as attested by Acts 2:10 (noting the presence of Jewish diaspora from Cyrene in Jersualem for Pentecost) and Josephus’ Against Apion 2.4 (noting that Ptolemy invited Jews to settle in Cyrene to strengthen his support base there). Given that this knowledge was apparently widespread and Cyrene was not an obscure region, as well as the dropping of the identification by the other canonical Gospels, the reference to Cyrene would have adequately served the purpose of identifying Simon and distinguishing him from the other Simons in the Gospel of Mark.
So, the reference to Cyrene makes sense as a distinguishing reference and follows Mark's practice in other passages. What is strange about the passage, therefore, is that it further describes Simon as “the father of Alexander and Rufus.” Nowhere else in Mark that I have found does the author identify anyone by reference to their geographic origin and familial relationship (though the information may be reported in the narrative it is not strung together, such as “Jesus of Nazareth, the son of Joseph"). This alone makes the passage stand out. But there is more. Another odd feature of Mark’s reference to Simon is his identification of Simon as the “father” of two sons, rather than as the “son” of his father.
Mark often identifies the men he names in his narrative by reference to their fathers: “Levi the son of Alphaeus,” “James the son of Zebedee,” “James the son of Alphaeus,” “James and John, the sons of Zebedee,” and “Bartimaeus, the son of Timaeus.” One man in Mark is identified in this way by his brother: “John the brother of James.” However, the extended reference is actually to “James the son of Zebedee and John the brother of James.” So Mark has identified James by reference to his relationship with another known character in the narrative and by indirect identification of his father (he shared the same father as his brother James).
But what about the identification of women in Mark’s narrative? No woman is identified as being “x, the daughter of” in Mark’s text. There are identifications of women as the “the mother of” particular persons: “Mary the mother of James the Less and of Joses, and Salome,” “Mary Magdalene and Mary the mother of Joses observed where He was laid,” and “Mary Magdalene, Mary the mother of James, and Salome.” But Mark never extends the practice to the many instances of identification of male figures by their familial relations. Nor does he do so after identifying the woman by her place of origin.
All told, there is a convergence of at least three unusual identification practices in this one reference. Mark identifies a tertiary character by name, identifies him both by his place of origin and his familial relationships, and takes the further unusual step of identifying a man by reference to his two sons, by name. What is the reason for this convergence? It is not even clear why Mark would refer to him by name, rather than referring -- as he does many other places -- to “a man in the crowd” being forced to carry the cross. There is something special about Simon that prompted the extended reference. Or, perhaps, what is special is not Simon per se, but his sons, Alexander and Rufus. If Mark’s audience was familiar with Alexander and Rufus then the string of convergences makes more sense. It would explain why Simon is singled out for identification by name and by place of origin, as a lead into clarifying for the audience, like saying “this is the father of the Greek Jews already known to you, Alexander and Rufus.”
Many scholars conclude that the reason Mark refers to Simon by name and identifies him as the father of Alexander and Rufus is because Alexander and Rufus were known to Mark’s audience, likely as members of the Roman church. At the very least, they were known as witnesses of the event or transmitters of their father’s experience. See, e.g., James A. Brooks, Mark, NAC, page 256 (“The obvious reason for the mention of ‘Alexandria and Rufus’ is that Mark’s readers/hearers knew them.”); James R. Edwards, The Gospel According to Mark, page 471 (“The names are presented as though Simon is unknown to Mark’s readers, but that Alexander and Rufus are known to them”); Robert H. Grundy, Mark, A Commentary on His Apology for the Cross, pages 943-44 (“The personal names also imply that Alexander and Rufus are known to Mark’s audience, to the audience of the pre-Marcan tradition, or to both of these audiences (and they might have been the same”); Martin Hengel, Studies in the Gospel of Mark, page 9 (“In Mark 15.21 Simon of Cyrene, the man who bears the cross, is identified -- quite unusually -- not by his father’s name but by his sons Alexander and Rufus, probably because these are still known to the audience of the Gospel. Matthew and Luke, however, omit both names; they no longer know what to make of them.”); C.S. Mann, Mark, The Anchor Bible, page 645 (“Only Mark tells us that he was the father of Alexander and Rufus, and again we assume that they were known either to Mark or to the community for which he was writing.”); Ben Witherington, The Gospel of Mark, page 394 (“Only Mark mentions his children (cf. Matthew), and this seems to suggest their familiarity to Mark’s audience.”). Notably, in Romans 16:13 Paul mentions a Rufus who was a member of the church in Rome -- the most commonly concluded place of origin for Mark's Gospel. This further buttresses the likelihood that at least one of the sons of Simon became a member of the young Christian movement.
Richard Bauckham believes that Mark’s use of their names and relations here is intended to signal that the event is reproduced from eye witness reports:
The case is not parallel to that of Mary the mother of James the little and Joses (Mark 15:40), where the sons serve to distinguish this Mary from others, because Simon (very common though this name was) is already sufficiently distinguished by reference to his native place, Cyrene. Matthew and Luke, by omitting the names of the sons, show that they recognize that. Nor is it really plausible that Mark names the sons merely because they were known to his readers. Mark is far from prodigal with names. The reference to Alexander and Rufus certainly does presuppose that Mark expected many of this readers to know them, in person or by reputation, as almost all commentors have agreed, but this cannot itself explain why they are named. There does not seem to be a good reason available other than Mark is appealing to Simon’s eyewitness testimony, known in the early Christian movement not from his own firsthand account but through his sons. Perhaps Simon himself did not, like his sons, join the movement, or perhaps he died in the early years, while his sons remained well-known figures, telling their father’s story of the crucifixion of Jesus. That they were no longer such when Matthew and Luke wrote would be sufficient explanation of Matthew’s and Luke’s omission of their names.
Bauckham, Jesus and the Eyewitnesses, page 52.
I think Bauckham may overcomplicate the issue. By signaling that Mark’s audiences knows Alexander and Rufus he is obviously signaling that his account can be verified by them and therefore is affected by eyewitness input to the tradition. I am inclined to agree with this conclusion. It is the best explanation for the unique convergence of so many rarities in Mark’s gospel: the naming of participants in the event, the identification of a tertiary participant by location and familial relation, and the use of his sons (again by name) as further identification.
An additional factor that leads me to conclude that Mark is signaling an eyewitness account by a person or persons known to his audience is the nature of the account itself. Mark does not need the narrative about Simon taking up the cross to establish his principal aims. Simon carries Jesus’ cross for a while, but the event has no particular theological or narrative significance. Nor is Simon a pious example meant to inspire early Christians in “taking up their” cross or serving Christ in some way. Simon does not offer his services. He is not moved by compassion or love for Jesus. He is drafted into carrying the cross. According to Mark, “they forced him to carry the cross.” In any event, Mark recounts plenty of other stories in his gospel that could be said to contain more important theological or narrative importance without naming the participants (much less naming them in such a unique way).
Further, there is no suggestion that Simon nor his children are witnesses to Jesus’ death, his burial, the discovery of the empty tomb, or any resurrection appearance. For his death, Mark refers to witnesses, again -- unusually for him -- identifying them by name: “Mary Magdalene, Mary the mother of James the younger and of Joses, and Salome.” (Mark 15:40). For the burial, Mark again lists the witnesses by name: Joseph of Arimathea, as well as -- again “Mary Magdalene and Mary the mother of Joses.” (Mark 15:43-47). For the discovery of the empty tomb and the announcement of Jesus’ resurrection, Mark again lists his witnesses: “Mary Magdalene, Mary the mother of James, and Salome.” (Mark 16:1-8). So, the important events -- both from a narrative and a theological point of view -- are covered by other witnesses.
There is obvious significance to concluding that Alexander and Rufus were known to Mark's audience and that their reference by name indicates eyewitness shaping of the tradition. As has often been noted, the existence of eyewitness participants in the early church during the transmission of the gospel tradition and authorship of the Gospels would have acted to control the tradition and prevent or mitigate the fabrication or exaggeration of stories in the narrative. Mark's reference to Simon, Alexander, and Rufus is evidence that just such controls existed. At the very least, the reference to Alexander and Rufus impacts the dating of the Gospel of Mark. "[T]he reference to these two children of Simon strongly suggests that this Gospel had to have been written during those children’s lifetimes, while they would be known by Mark’s audience. All other things being equal, this favors a date for this Gospel prior to the destruction of Jerusalem.” Witherington, The Gospel of Mark, page 394.