The earliest Mark could have written, if the testimonies of the Anti-Marcionite Prologue and Irenaeus are correct, was after the death of Peter and Paul. The most probable dates of Peter's martyrdom in Rome are 64-67 A.D. Paul probably died as a martyr there in 67-68 A.D. Clement of Alexandria and Origen both placed the composition of this Gospel during Peter's lifetime. This may mean that Mark wrote shortly before Peter died. Perhaps Mark began his Gospel during Peter's last years in Rome and completed it after Peter's death.
The latest Mark could have written was probably 70 A.D. when Titus destroyed Jerusalem. Many scholars believe that since no Gospel writer referred to this event, which fulfilled prophecy, they all wrote before it.
To summarize, Mark probably wrote this Gospel sometime between 63 and 70 A.D.
