This pious custom began with the offering of a holy Jewish woman's veil to wipe the spittle, dirt and blood from the countenance of Our Lord during His agonizing journey to Calvary.
Her name was Veronica. The reward for her courageous act of mercy was the miraculous impression of His Face on her veil.
Pope Pius XII officially instituted the Feast of the Holy Face of Jesus for celebration on Shrove Tuesday.