
Two letters, one name
The Chi-Rho
The shortest way to write Christ.
Chi (Χ) and Rho (Ρ) are the first two letters of Χριστός, Christos, the Greek word for Christ. Laid over one another they make a single mark, small enough to cut into stone in a few strokes.
The sign belongs above all to the fourth century. Before the Battle of the Milvian Bridge in 312, the writer Lactantius tells us, Constantine had his soldiers mark their shields with the sign of Christ. A later account by Eusebius describes the labarum, an imperial standard crowned with the Chi-Rho. Within a generation it was on coins, on sarcophagi and on the walls of the catacombs.
“In hoc signo vinces. In this sign, conquer.”



