in the New Testament the instrument of crucifixion, and hence
used for the crucifixion of Christ itself (Eph. 2:16; Heb. 12:2;
1 Cor. 1:17, 18; Gal. 5:11; 6:12, 14; Phil. 3:18). The word is
also used to denote any severe affliction or trial (Matt. 10:38;
16:24; Mark 8:34; 10:21).

The forms in which the cross is represented are these:

1. The crux simplex (I), a "single piece without transom."

2. The crux decussata (X), or St. Andrew's cross.

3. The crux commissa (T), or St. Anthony's cross.

4. The crux immissa (t), or Latin cross, which was the kind of
cross on which our Saviour died. Above our Lord's head, on the
projecting beam, was placed the "title." (See CRUCIFIXION

After the conversion, so-called, of Constantine the Great
(B.C. 313), the cross first came into use as an emblem of
Christianity. He pretended at a critical moment that he saw a
flaming cross in the heavens bearing the inscription, "In hoc
signo vinces", i.e., By this sign thou shalt conquer, and that
on the following night Christ himself appeared and ordered him
to take for his standard the sign of this cross. In this form a
new standard, called the Labarum, was accordingly made, and
borne by the Roman armies. It remained the standard of the Roman
army till the downfall of the Western empire. It bore the
embroidered monogram of Christ, i.e., the first two Greek
letters of his name, X and P (chi and rho), with the Alpha and
Omega. (See A T0000001.)