Chi-Rho
A monogram of the first two letters of Christ's name in Greek, used by Christians as a symbol of Christ.
Meaning
Chi (Χ) and rho (Ρ) are the first two letters of Christos, the Greek for 'anointed one'. Written one over the other they form a monogram that stands for Christ himself. It appears on altar frontals, vestments, church doors and grave markers.
Origin and history
The monogram is older than its Christian meaning. Greek scribes used the same pair of letters to abbreviate words that begin with them, and it appears on coins of Ptolemy III of Egypt in the 3rd century BCE.
Its Christian history begins with Constantine. Before the Battle of the Milvian Bridge in 312, the writer Lactantius says, he had the sign marked on his soldiers' shields; Eusebius later described it at the head of the labarum, the imperial standard. Historians still debate what Constantine saw and when.
Within decades it was carved on sarcophagi and painted in the catacombs of Rome, often between the letters alpha and omega. It has never fallen out of use, and today appears in Catholic, Orthodox, Anglican and Protestant churches alike.
How the form changed
a Two letters (Greek alphabet). Chi (Χ) and rho (Ρ), written separately.
b A scribe's abbreviation (From the 3rd century BCE). Χ laid across the stem of Ρ to shorten Greek words.
c Constantine's emblem (312 CE). On shields and at the head of the imperial standard.
d In a victory wreath (Mid 4th century CE). Carved on sarcophagi inside a laurel wreath, between alpha and omega.
See also
Sources
- The Oxford Dictionary of the Christian Church, Oxford University Press
- Lactantius, On the Deaths of the Persecutors, 44.5
- Eusebius, Life of Constantine, 1.28–31
Last reviewed September 23, 2026.