AS we near the end of the 12 Days of Christmas we get to the 11 Pipers Piping. These Pipers are the faithful Disciples. Why eleven and not twelve? Judas is not counted because he betrayed Jesus. Also, the eleven followed Jesus’ mission up to their deaths.
It is interesting to note that the only Disciple not to be martyred was John the Beloved. If you want to talk faithful Disciple then he is the one. He risked being killed himself by accompanying Jesus mother and Mary Magdalene during the whole crucifixion process. The others ran and Peter even denied knowing Jesus. Because of His faithfulness and being there in the open providing comfort to Jesus mother by being there (ministry of presence), John seemed to understand people enough that they could not kill him but the Greeks and Romans exiled him to a cave on Patmos.
What happened to the rest during this time is well known and we have a page dedicated to the Apostles here: Lessons from The Apostles
When the Disciples ran where did they go? Did they return to the Upper Room and lock the door? Did they disburse and meet up later? There is no real understanding of that time except for the absolutes known because of the fast turbulent pace in which everything happened. But we do know that they all gathered within hours after Jesus died and were almost all present for Jesus first meeting with them after the Resurrection. They all did see Him and were taught much more for the 40 days before the Ascension.
The Acts of the Apostles is really only the tip of the iceberg for what the Apostles accomplished after Jesus left. We have the record of only a few written in Scripture but the rest are recorded in the annals of history and reported by the Catholic Church. I am guessing that letters were written to James, Peter, and John and the areas they were in were then researched to actually figure out their demise. One thing is certain, they faithfully served Christ.