Chi Rho is an ancient Christian symbol, a Christogram that is made by overlaying the initial two
letters (in capital) of the Greek word ‘Christos’ meaning ‘Christ’. Pronounced as ‘KEE-roe’, the
monogram looks to have been formed with the English alphabets X and P. In fact, it is the Greek
alphabet ‘chi’ that resembles X and ‘rho’ that looks like P. The Chi Rho symbol represents both
Christ and Christianity and exists today in several variations. It is also behind the practice of
abbreviating ‘Christ’ in Christmas to ‘X’.
Though the contemporary representation of Chi Rho symbol show the two lines of chi crossing
at 90 degrees, its early symbols have them crossed at angle formed by intersection of the
celestial equator and the solar ecliptic path.
The Chi Rho symbol has pre-Christian connections and is believed to have been revered by the
pagan Greeks as representative of good fortune. Pagan Greek scribes used the symbol in the
margin to mark passages they considered especially significant or relevant, with the letters Chi
and Rho denoting ‘chreston’ that means ‘good’. The sign has also been found on the coins of
Ptolemy III (246-222 BCE)
However, Chi Rho gained widespread popularity and found much use by the Christians after
it was adopted by the great Roman military commander, Emperor Constantine I as a vexillum
(military standard). History has it that the symbol appeared to Constantine in a vision or dream
before he fought the Battle of the Milivian Bridge outside Rome in 312 A.D. and he had it put
on his soldiers’ shields. His army won the battle and subsequently, the deeply affected emperor
legalized the religion of Christianity across the Roman Empire. Later, the symbol also appeared
on the coins of Emperor Constantine and his successors.