Tau cross
[9] In the Trial of the Court of the Vowels of non-Christian Lucian (125 – after 180), the Greek letter Sigma (Σ) accuses the letter Tau (Τ) of having provided tyrants with the model for the wooden instrument with which to crucify people and demands that Tau be executed on his own shape: "It was his body that tyrants took for a model, his shape that they imitated, when they set up the erections on which men are crucified.
For my part I know none bad enough but that supplied by his own shape—that shape which he gave to the gibbet named σταυρός after him by men"[10] The Greek word σταυρός, which in the New Testament refers to the structure on which Jesus died, appears as early as AD 200 in two papyri, Papyrus 66 and Papyrus 75 in a form that includes the use of a cross-like combination of the letters tau and rho.
The Hospital Brothers of St. Anthony, known as the Antonines, were a Catholic religious order of the Latin Church founded at the end of the 11th century.
A staff of that kind is represented in his hand in a painting by the German Renaissance painter Matthias Grünewald (c. 1470 – 1528) on an outer panel of his Isenheim Altarpiece.
As Omer Englebert recounts in his biography of Francis, the Pope, after describing the sad situation of the Holy Places trampled by the Saracens, lamented the scandals that discredited the flock of Christ and threatened it with divine punishment if it was not amended.
He evoked the vision of Ezekiel, when the Lord, patience exhausted, exclaims with a powerful voice:[19][page needed] "'Come near, you who watch over the city; come near with the instrument of extermination in your hands.'
Those are you, Council Fathers, who, using all the weapons you have at hand: excommunications, dismissals, suspensions and interdicts, you have to relentlessly punish how many are not marked with the propitiatory tau and are obstinate in dishonoring Christianity.
In his Lateran speech, Innocent III had marked with the tau sign three classes of predestined: those who enlisted in the crusade; those who, prevented from crossing paths, fight against heresy; finally, the sinners who really commit themselves to reforming their lives.
Francis, who participated in the council as superior general of an order approved by the church, must have taken Innocent III's invitation very seriously, since, according to his companions and his first biographers, he loved and revered the tau, "because it represents the cross and means true penance".
In his conversations and sermons he often recommended it, and drew it as a signature in all his letters and writings, "as if all his concern was to engrave the sign of the tau, according to the prophetic saying, on the foreheads of the men who moan and weep, truly converted to Christ Jesus.
