Monsignor Martin B. Hellriegel (1890-1981), an Apostolic Protonotary, was one of the giants of the 20th century Liturgical Movement that Pope Pius X inspired. A native of Heppenheim, Germany, his most productive years were spent in America, where he was chaplain to the Most Precious Blood Sisters in O'Fallon, Missouri, then pastor of Holy Cross parish in St. Louis.