The first recorded reference to the TAU is from Ezekiel 9:4, "Go through the city of Jerusalem and put a TAU on the foreheads of those who grieve and lament over all the detestable things that are done in it." The TAU is the last letter of the Hebrew alphabet and looks very much like the letter "T".
At the Fourth Lateran Council, on November 11, 1215, Pope Innocent made reference to the TAU and quoted the above verse in reference to the profaning of the Holy Places by the Saracens. It is widely accepted that St. Francis was present at the Fourth Lateran Council and that he heard the words of Pope Innocent III when he said, "The TAU has exactly the same form as the Cross on which our Lord was crucified on Calvary, and only those will be marked with this sign and will obtain mercy who have mortified their flesh and conformed their life to that of the Crucified Savior. From then on, the TAU became Francis' own coat of arms.
Francis used the TAU in his writings, painted in on the walls and doors of the places where he stayed, and used it as his only signature on his writings.
St. Bonaventure said, "This TAU symbol had all the veneration and all the devotion of the saint: he spoke of it often in order to recommend it, and he traced it on himself before beginning each of his actions."
Thomas of Celano, another Franciscan historian writes, "Francis preferred the Tau above all other symbols: he utilized it as his only signature for his letters, and he painted the image of it on the walls of all the places in which he stayed."
In the famous blessing of Brother Leo, Francis wrote on parchment, "May the Lord bless you and keep you! May the Lord show His face to you and be merciful to you! May the Lord lift up His countenance upon you and give you peace! God bless you Brother Leo!" Francis sketched a head (of Brother Leo) and then drew the TAU over this portrait.
THE TAU AS OUR FRANCISCAN SYMBOL
Where did the TAU come from and what does it mean? (Rhymes with "How") Simply and basically, the TAU represents the Cross. It is also the last letter of the Hebrew Alphabet. However, the two major influences on Francis concerning the TAU were the Antonians and the Fourth Lateran Council.
St. Francis borrowed the TAU and what it meant to him from the Antonians. They were a religious community of men founded in 1095 whose sole function was to care for lepers. They were disbanded as an Order by the Church in the 1500's because leprosy was no longer a problem and many of the religious orders had fallen into Theological problems. On their habit was painted a great TAU cross. Francis was very familiar with these men because they staffed the leper house in Assisi and the hospital of St. Blase in Rome where Francis went to stay. This is now the church of San Francisco A Ripa.
Every time you see St. Anthony, "the Abbot or Hermit" in art, he is portrayed with the TAU.
St. Francis was exposed to the TAU through the direct influence of the Antonians, but the greatest influence of all that made the TAU so dear to Francis, whereby it became his signature, was the Fourth Lateran Council.
Pope Innocent III opened the Council on November 11, 1215, with these words: "I have desired with great desire to eat this Passover with you." (Luke 22-15.) Innocent announced that for him, for the Church, and for every Catholic at the time, the symbol they were to take as the sign of their Passover was the TAU Cross.
He incorporated into his homily the statement from Ezekiel (9:4) that the elect, the chosen, those who are concerned will be marked with the sign of the TAU. He explained that this Passover is a three-fold Passover.
Every Catholic must be involved in this triple Passover: A Corporal Passover, a Spiritual Passover and an Eternal Passover.
These became some of the most precious themes of Francis' preaching. He must have taken them so deeply to heart that when Pope Innocent III ended his homily with "BE CHAMPIONS OF THE TAU", Francis evidently took that as a personal statement and made the TAU his own symbol: a symbol for his order, his signature, painted it everywhere, and had great devotion to it for the rest of his life.