Denotes the presence of Christ, and is also referred to as the Sign of Constantine, because Constantine had put it on the labarum. There are the apocalyptic letters a and w between the arms of the cross (Rev. 1:8, 21:6, 22:13). The Monogram is surrounded by a palm-leaf wreath, symbolizing a reward for victory. For the first time it is clearly seen on the coins of Constantius (306-337) and Constans II (337-350), and it may be traced up to 451 or 475.