Wenham, John. "Chapter Eight: Mark's Gospel: Further Considerations." Redating Matthew, Mark, and Luke: A Fresh Assault on the Synoptic Problem. Downers Grove, Illinois: InterVarsity Press, 1992, 173-182.
The placement of Mark as founder of the church in Alexandria further informs our understanding of the time and origin of Mark's Gospel. Eusebius places Mark in Alexandria, with his written Gospel, in time to be succeeded by Annianus in Nero's eighth year (Wenham 1992, 174). This was a universal explanation of the founding of the church in Alexandria from early Christianity. Manuscript P52, from Egypt, from the early second century, strongly suggests that the Gospel was present there from an early time (Wenham 1992, 175).
Wenham further adduces 7QS, sealed in Qumran in 68, as evidence of Mark's Gospel being known at that time, as the scroll contains a part of Mark 6:52f (Wenham 1992, 177). Spelling irregularities in the passage suggest an Egyptian origin of the text (Wenham 1992, 178).
Internal evidence in Mar's Gospel also, as far as Wenham is concerned, speaks to early composition drawn primarily from oral narratives. This further suggests the accuracy of early testimony of the Church, asserting that it was based on Peter's preaching (Wenham 1992, 180).