Among the early symbols of Christianity, the letters XP (chi-rho) hold a special place, carrying a deep theological and historical meaning with them. This sign, which is the monogram of Christ, comes from the first two letters of the Greek word “Χριστός” (Christ), i.e. Chi (Χ) and Rho (Ρ). The use of these letters dates back to the 4th century CE, and their importance was reinforced during the times of Emperor Constantine the Great (who lived from approx. 272-337 CE), who introduced chi-rho as a symbol of his rule after a legendary revelation before the Battle of Milvian Bridge (312 CE).
According to historical accounts, Constantine had a vision before the key battle in which he saw the Chi-Rho symbol in the sky and the words “In hoc signo vinces” – “In this sign thou shalt conquer”. Believing in divine intervention, Constantine adopted this sign as his symbol of victory, and after triumphing over his opponents, he became the first Roman emperor to favor Christianity officially.
At a time when Christians were persecuted, symbols like XP were a subtle yet powerful way to express faith. These letters could appear on graves, liturgical vessels or seals without revealing their religious meaning at first glance. However, they were a sign of Christ for believers.
The XP not only represented Christ but also served as a reminder of the saving power of the cross on which Christ died and the triumph over death. Combined with other symbols, such as the fish (ichthys), XP formed part of the rich repertoire of signs used by the first Christians.
The letters XP, although simple in form, were of great importance to both the theology and practice of early Christianity. Their story exemplifies how symbolism can express faith, hope and victory over adversity.