Some of us were discussing an issue this am that we could not resolve: when
the celebrant at Mass turned away from the congregation to face the
wall/apse. Some thought it was in the Carolingian period, accompanying a
rise in the sense of awe and fear in the presence of God, so that the priest
becomes chief suppliant and go between; others placed the turn in the 13th
century perhaps associated with the heightened devotion to the Eucharist and
the "secrecy" that would dictate its confection being hidden from the
congregation. What is the real answer?