They replied to him, "Caesar's."
So Jesus said to them,
"Repay to Caesar what belongs to Caesar
and to God what belongs to God."
They were utterly amazed at him.
-- Mk 12:13-17
From the beginning of Christian history, the assertion of Christ's lordship over the world and over history has implicitly recognized that man should not submit his personal freedom in an absolute manner to any earthly power, but only to God the Father and the Lord Jesus Christ: Caesar is not "the Lord". "The Church. . . believes that the key, the center and the purpose of the whole of man's history is to be found in its Lord and Master."
-- CCC 450
(Celebrating the Year of Saint Paul: Mamertinum prison, Rome. Traditional place of Paul's imprisonment in the Eternal City. Photo by blog author.)