Origin: before 1100; Middle English chanceler < Anglo-French < Late Latin cancellārius doorkeeper, literally, man at the barrier (see chancel, -er2); replacing Middle English canceler,Old English ≪ Late Latin, as above
early 12c. (a variant form existed in O.E.), from O.Fr. chancelier, from L.L. cancellarius "keeper of the barrier, secretary, usher of a law court," so called because he worked behind a lattice at a basilica or law court (see chancel). In the Roman Empire, a sort of court