Chi Rho
The Chi Rho (☧, English pronunciation KY-ROH; also known as chrismon) is one of the earliest forms of the Christogram, formed by superimposing the first two (capital) letters—chi and rho (ΧΡ)—of the Greek ΧΡΙΣΤΟΣ (rom: Christos) in such a way that the vertical stroke of the rho intersects the center of the chi. The Chi Rho symbol was used by the Roman Emperor Constantine the Great (r.