The Tau is the 19th letter of the Greek alphabet, and it looks similar to the English letter “T”. However, it is really cruciform in shape, that is, it has the same form as the cross on which our Lord and Savior Jesus Christ was crucified on Calvary over 2000 years ago.
Historically, the TAU configuration was the last letter of the Hebrew alphabet, and it signified the end or the accomplishment of the word revealed to humanity by God, over the centuries. The Old Testament in Ezekiel 9:4 referred to the symbol of the TAU when it said: “Go all through the city, all through Jerusalem, and mark TAU on the foreheads of all who deplore and disapprove of all the filth practiced in it.” The prophet Ezekiel was speaking of God’s faithful – those who kept the Covenant – being marked with a TAU on their foreheads.
How did the TAU become associated with St. Francis of Assisi? It was in Rome, in the year 1215, that Francis heard Pope Innocent III open the Fourth Lateran Council with a sermon that included reference to the passage in Ezekiel. The Holy Father spoke about God’s faithful ones being marked on their foreheads with the TAU. The Pontiff urged conversion, penance and salvation, and the TAU was symbolic of this. This had a profound effect on St. Francis of Assisi who decided to make wide use of it himself.
Eventually, the sign of the TAU was used by the followers of St. Francis, as well as many other Christians, not only because of its historic significance in early Scripture, but because of its resemblance to the cross on which Christ died.
The other representations on the official insignia of the Franciscan Order show two arms – one signifying Christ, the other St. Francis. The arms of Christ and St. Francis are crossed over the TAU. For those of us who are Franciscans, it is our coat-of-arms. It is symbolic of the challenge and the mark we have accepted – to transform our lives, and become faithful followers of Christ, by living the Gospel life, in the spirit of our Seraphic Father Francis of Assisi.