St. Gertrude the Great is invoked for souls in purgatory and for living sinners. Our Lord told St. Gertrude that the following prayer would release 1000 souls from purgatory each time it is said. The prayer was extended to include living sinners as well.
"Eternal Father, I offer Thee the Most Precious Blood of Thy Divine Son, Jesus, in union with the Masses said throughout the world today, for all the Holy Souls in Purgatory, for sinners everywhere, for sinners in the universal church, those in my own home and within my family. Amen."
Gertrude was born January 6, 1256, in Eisleben, Thuringia, Holy Roman Empire. As a young girl, she joined the Benedictine monastery in Helfta. She dedicated herself to her studies, becoming an expert in literature and philosophy. She had various mystical experiences, including a vision of Jesus, who invited her to rest her head on his breast to hear the beating of his heart. She died 17 November, 1301 or 1302. Although never formally canonized, Pope Clement XII inserted her name in the Roman Martyrology in 1677. Her feast is November 16.