One of the popular indicators of the supposed war on Christmas is the use of the abbreviation Xmas. The well motivated, if grating, “Don’t take Christ out of Christmas” alludes not so subtly to the abbreviation. The former Anglican bishop of Blackburn, Alan Chesters, advised his clergy against using it. Jane Wyles, editor of the Anglican C Magazine, summed up much Christian sentiment when she criticized the “glib way people substitute Christ with this anonymous ‘X’. It’s all part of the PC picture—Christianity gets squashed into a smaller and smaller corner.” …

Xmas is, though, a much more venerable abbreviation than many suppose. The X signifies the Greek letter chi, which was traditionally combined with P, or rho, to signify the name of Christ. Constantine instructed his soldiers to scrawl the letters on their shields before the Battle of the Milvian Bridge, his victory in which led to the unlikely establishment of a Christian empire. Far from a symbol of secularization, then, Xmas carries echoes of the clash of battle that inaugurated political Christendom. The abbreviation’s use in English dates back to 1021, when an Anglo-Saxon scribe saved himself space by writing XPmas. The P was dropped but the term soldiered on: Coleridge used Xmas in his letter writing. The wags at Punch pressed it into service as a verb, Xmassing …