Shibboleth: A Templar Monitor, by George Cooper Connor, , at sacred-texts.com
A fable invented by the sycophants of Constantine has been dignified into a Motto of the valiant and magnanimous Order of the Temple, after passing through various gradations of fortune. The fable is thus related:
Constantine the Great was declared Augustus and Pontifex Maximus after he had vanquished the army of Marentius, under the walls of Rome. He professed Christianity. It was during his march on . Rome, and while encamped near Mentz, that he was reported to have seen in the sky a fiery Cross, bearing the inscription Ἐν τουτῳ νικα
"With this sign you will conquer." He had this symbol, known as the Cross of Constantine, emblazoned on the Imperial Standard, called the Labarum.
How the Chi Rho Cross came to be changed into the Passion Cross of the Latin Church, and the Greek inscription into corresponding Latin, is clearly explained by the conquest of the Eastern by the Western Church. When the Church of Rome became mistress of the world everything had to submit to its dictation, and all popular myths gravitated to its use and emolument.
It is deeply to be regretted that the name of Constantine, who murdered his father-in-law, his brother-in-law, his nephew, his son, and finally his wife, Fausta, should be associated with this popular myth, and this beautiful symbol. That he was ever converted to Christianity we deny, and his being baptized only in the year in which he died, nearly a quarter of a century after his professed conversion, proves his deception.
It is not established that the ancient Templars used either the Greek or the Latin inscription so popular with the modern Templars.
[paragraph continues] They did use the Passion Cross on the Beauceant, and as a part of their armorial bearings.