In the Church’s traditional calendar today we celebrate St. Peter the Martyr, also known as Peter of Verona.
St. Peter Martyr was a Dominican who preached against the Cathars around Milan. He was so effective that the Cathars hired an assassin who in 1252 killed Peter with an axe or large blade to the head. When he was struck in the head, Peter dipped his fingers in his own blood and wrote “Credo in Deum” on the ground as he recited the Apostles Creed before dying. His assassin converted and is now venerated as a Blessed. Peter himself was canonized with blinding speed the very next year by Innocent IV (Fieschi).
Peter was also an effective inquisitor. He was known to be a clement judge for those who confessed their sins and crimes. Hence, Peter Martyr is the patron saint of inquisitors.
He id depicted in a Dominican habit with a big blade sticking out of his head. He is, therefore, also invoked against headaches. Bl. Idelfonso Schuster, once Archbishop of Milan and a great Benedictine liturgist wrote a prayer for headaches. Since I know some people who suffer from migraines, here it is:
O God, who did grant to your Blessed Priest and Martyr Peter the grace to write with his blood that Symbol of the Faith which, after he had diligently learned it as a child, and then become a Preacher of your Gospel, he preached undaunted to the people against the errors of the heretics; through his prayers grant that Your Church might preach the Faith and confirm it in good works. Through Christ our Lord.
We should probably bring back the Inquisition, by the way. The Inquisition is poorly understood and many lies and black false legends hem it in.
Here is something you might not know.
There are two special blessings in honor of St. Peter the Martyr, one for Holy Water – on any day – using a relic of St. Peter Martyr and one on his feast day for palms and other branches. They are both in the Rituale Romanum, assumed from the Dominicans books. Any priest can use these now. I found a translation at NLM.
Here is the blessing of water.
V. Our help is in the name of the Lord.
R. Who made heaven and earth.
V. The Lord be with you.
R. And with your spirit.
Let us pray. O God, who for the salvation of the human race did institute the greatest mysteries in the substance of water, mercifully be present to our invocations, and pour forth upon this element of water Thy bless+ing, which we seal by the power of the blessed Peter, Thy Martyr; so that though his intercession, it may be a salutary remedy for your faithful, driving out evil spirits from them, and warding off illnesses and infirmities of body and spirit; and grant that all who drink of it or are sprinkled with it may be delivered from every adversity of body and soul, and regain health in their whole being. Through Christ our Lord. R. Amen.
Let us pray. Almighty everlasting God, we humbly implore Thy boundless clemency, that Thou may deign to bless + by Thy indescribable power these Thy faithful people, who devoutly come to (venerate) the relics of the blessed Martyr Peter, and ask for his prayers; so that by his intercession, delivered from every ailment of mind and body, protected here and everywhere by Thy mercy, and saved by Thy grace, they may merit, after the course of this way and life, to come unto eternal joy. Through Christ our Lord.
There are also blessings of Holy Water in honor of other saints, such as Sts. Vincent Ferrer, Albert the Carmeltite, Ignatius of the Jesuits, Vincent de Paul and Raymond Nonnatus, the Mercedarian.
The prayer for Holy Water in honor of St. Petery Martyr mentions, as do other blessing prayers for water, the driving out of demons.
At the Art Institute in Chicago there is a medieval series of the life of St. Peter. He is sprinkling Holy Water and driving out a demon.
Hence, if any of your parishes have a relic of St. Peter Martyr, you might have some Holy Water blessed with it. Remember, the blessings in force in 1962 with the Rituale Romanum must be done in Latin or else, as the Rituale itself says, they do nothing. No… really. (Cf. Title VIII, Ch. 1, no. 2: Benedictiones sive constitutivae sive invocativae invalidae sunt, si adhibita non fuerit formula ab Ecclesia praescripta.)