There were actually 3 ST Georges, 1 German, 1 Roman and 1 Cappadocian.

In highschool I was taught that it was the Roman one who was the Patron Saint as he was a legionaire who served some time in England (hence the connection) then, when back in Rome stood up for the Chriustians being executed and shared their fate. Not being religious myself however I have no idea if this is true or not