The Tau — A Franciscan Emblem
The sign Tau has its origin in biblical antiquity and is the last letter of the Hebrew alphabet. It has a special significance for Franciscans because Francis adopted it as his personal seal and encouraged his companions to do the same. Describing Francis preference for this sign, St. Bonaventure writes in his Life of Saint Francis: ‘This Tau symbol had the saint’s deep veneration and devotion; he spoke of it in order to recommend it and he signed himself with it before beginning any action’ (Lm 2:9).
In this way, Bonaventure cleverly bestows on Francis’ use of the Tau an eschatological significance. That Francis was aware of the deep spiritual significance of the Tau is manifested in the way he used it to autograph his blessing for Brother Leo. The holograph called the Chartula has the Praises of God on one side, and, the Aaronic Blessing (Num.6:24-26), now commonly known as the Blessing of St. Francis, on the other.
The Tau was for Francis and his companions a symbol of their total commitment to Christ in poverty and penance, and for whom they carried the cross in their bodies for salvation of the Church. This sign Francis and his friars adopted and used at the
wish of Pope Innocent to symbolise their loyalty and active support of their consiliar reforms.
Minor Life of St. Francis by St. Bonaventure
Major Life of St. Francis by St. Bonaventure