Father William R. Bonniwell, O.P., spent a large part of his life as a Dominican priest and scholar. He was ordained in 1914 and went on to become the Director of the Preachers' Institute at Washington, D.C. He also spent a considerable amount of time in Italy while gathering information on Blessed Margaret of Castello, which he eventually published in his book The Life of Blessed Margaret of Castello. Father Bonniwell is also the author of Liturgical Spirit of Lent, History of the Dominican Liturgy, Interpreting Sunday Mass, What Think You of Christ?, and Martyrology of the Sacred Order of Preachers. He died in 1984 after nearly suffering blindness.