Cancelli are lattice-work, placed before a window, a door-way, the tribunal of a judge, or any other place. Hence the occupation of Cancellarius, which originally signified a porter who stood at the latticed or grated door of the emperor's palace.
The emperor Carinus gave great dissatisfaction by promoting one of his Cancellarii to be Praefectus urbi. The cancellarius also signified a legal scribe or secretary, who sat within the cancelli or lattice-work, by which the crowd was kept off from the tribunals of the judges.
The chief scribe or secretary was called Cancellarius, and was eventually invested with judicial power at Constantinople, but an account of his duties and the history of this office do not fall within the scope of the present work. From this word has come the modern Chancellor.