Thanks for the replys,I am looking at 10"thick concrete base approx 2ft square with an 8" high plinth.
I had thought of a 2" wide galvanized strap moulded into the footings and secured to the posts with lag screws.
I am using green oak from Lord Inglesfields estate [very grand].
Termites thankfully are not a problem and our little woodworm only penetrate sapwood.