I spent the day today walking around the suburbs of Pittsburgh, soaking up the cold and the snow as best I could, storing it away mentally to be recalled throughout the long bright winter in San Diego. And with the all the lights, signs, and half-inflated Santas, well, in the air there’s a feeling of Christmas.

Or might one say Xmas?

One might of course, but in so doing one runs the risk of offending a few people. For instance, these folks, who view the use of Xmas as a way for the secular to omit Christ from Christmas. This is a widely held belief, and one that people often feel strongly about; a search for “Christmas not Xmas” on Facebook netted 200 groups and 34 pages pushing for use of the word Christmas instead of Xmas. It’s even led to poetry:

We surely would not write “X-ian”
For the Christians here on earth,
Then why do many write “X-mas”
For the day of the Savior’s birth?

But, as so often happens, the poem is mistaken. There is nothing devious or censorious about Xmas, or even Xian for that matter; X is an old abbreviation for Christ. And when I say old, I mean old: 900 years old in English, and 1700 in Latin/Greek.

In fact, it all goes back to the Roman Emperor Constantine I, best known for his giant marble head, his founding of Constantinople, and his much-publicized acceptance of Christianity on the eve of the Battle of the Milvian Bridge in 312 AD. After the battle, Constantine adopted the labarum — ☧, a juxtaposition of the Greek letters chi (X) and rho (P) as a symbol for Christ — as his monogram. Although the symbol ☧ itself and the abbreviation XP pre-dated Constantine, it was his use of them that really launched them to prominence.

So why use “Chi-Rho” anyway? Well, it’s an abbreviation for “Christ”, which in Greek is “Χριστός”. Note those first two letters, chi and rho. That means people have been abbreviating Christ with an X (or an XP) for 1700 years. In fact, these sorts of abbreviations and word games were something of a calling card of the early Christian church. The “Jesus fish” so prevalent on on the back-ends of cars has “ΙΧΘΥΣ” inside of it, an acrostic for the ancient Greek “Ἰησοῦς Χριστός, Θεοῦ ͑Υιός, Σωτήρ”, which means “Jesus Christ, Son of God, savior”. Before it became a foot soldier in the bumper sticker wars, this acrostic was used as a marker in the early Christian underground. Other common abbreviations — also known as Christograms — include the INRI (from the Latin for “Jesus Nazarene, King of the Jews”) on crucifixes, the IHS (from the first three letters in “Jesus” in Greek) on tombstones, or the contracted nomina sacra in early Greek scriptures. These abbreviations are throwbacks to the exciting early years of Christianity, not some modern plot to snuff out Jesus.

That’s all well and good, but what about the X in English? Was it just a Roman-era Christian symbol that’s only now being resurrected by heathens to cover up the Christ in Christmas? Nope. In the Old English Anglo-Saxon Chronicles, written sometime before 1123, we see the chi-rho abbreviation in Christ’s mass, the progenitor of the word Christmas:

Her on {th}isum {asg}eare to X{ptilde}es. mæssan heold se cyng Heanri{asg} his hired on Westmynstre.

The OED lists further examples of such X abbreviations from then until now — not just in Xmas, but also in Xtian (for Christian). Aldous Huxley used it in 1915 (The ethics are identical with Xtian ethics), Ezra Pound in 1940 (They drove the Xtians out of Japan), and D. Jones in 1960 (what the present notion of Xtianity boils down to). So the poet I quoted above is completely mistaken; we surely might write X-tian for the Christians here on Earth. It’s not a common abbreviation anymore, but Xmas still is. Here’s even a neat example from Wikipedia, with Xmas used in a postcard in the good ol’ days around 1910:

So fear not, traditionalists! You can use Xmas without fear of offending God! The only concern with Xmas is that as an abbreviation, it’s a bit informal. I wouldn’t necessarily recommend it on your letterhead, but if someone suggests you’re impious for using Xmas, let ’em know how traditional you are. 1700 years traditional, baby!