Chi-rho (Accepted)

The chi-rho is a Christian symbol popularized by the Emperor Constantine.  It consists of the first two (Greek) letters of Christos, conjoined into a monogram.  Though found in period art – the illustration is taken from a 4^th C. coin – the chi-rho does not appear to have been used in period heraldry.  See also cross, cypher charges.

Basilius Phocas bears:  Gules, a chi-rho argent within an orle of bezants.

Artus Quintus bears:  Argent, a chi-rho and a bordure gules.

Konstantinos of Rath an Oir bears:  Purpure, a chi-rho and a chief Or.