Legion near Judea at time of Jesus

[Nathan Ross]

what legion or auxilia did this centurion belong?

I think we can gather from the accounts in Matthew and Luke that the centurion lived in the town: he had links with the community elders and had paid to have a synogogue built. He also seems to have spoken Aramaic. So he was probably a local man originally, and perhaps was centurion of one of the locally-raised auxiliary cohorts (maybe the Cohors Sebastanorum mentioned above?).

My guess would be that he was either stationed in the town for some reason (individual soldiers or small groups were sometimes detached to towns and villages for various purposes, but in this case he must have been there for quite a long time), or he had retired from the army and settled at Capernaeum. At a push he could have been a retired legionary officer, but as there seem to have been few if any legionary troops in the vicinity I'd say it would have been unlikely for one to be drawn to live in such an isolated place.