Clement Breen, the son of Solomon and Margaret O'Shea Breen, was born in Chicago, Illinois, on November 15, 1904. He was baptized at Saint Andrew's Church on North Paulina Street, on December 11, and confirmed at Holy Cross Church in the Spring of 1916.

After the family moved to Minneapolis, Minnesota, Clement at tended the Pro-Cathedral Grade School there and St. Thomas Academy in St. Paul, graduating in 1923. Anticipating a business career he studied economics and accounting at the University of Minnesota and began his college studies at St. Thomas College but transferred to Columbia (later Loras) College in Dubuque, Iowa. He was active in debate and drama as well as the college's publications, being elected later as editor of the Purgold, the college yearbook. After graduating, at age twenty-six, in 1931, Clement Breen applied to the novitiate of the Dominican Order. During his college years he had taken pre-seminary courses and had majored in philosophy, but he had not committed himself to a diocese. The college president recommended him to Father T.S. McDermott, the Dominican Provincial in New York, as "a young man of refined manners, of average talent and of excellent character and reputation."

Clement received the Dominican habit at St. Rose Priory in Springfield, Kentucky, on August 15, 1931, and the religious name, Brother Matthew. He made his simple profession one year later, August 16, 1932, and proceeded with his class to begin studies in the houses of study in River Forest, Illinois; Somerset, Ohio; and Washington, D.C. He was ordained to the priesthood at St. Dominic's Church in Washington, D.C., on June 16, 1938, a member of the largest ordination class in the history of the Dominicans in the United States.

As a member of the newly established Midwestern Province, the Province of St. Albert the Great, Father Breen went to his first assignment at Blessed Sacrament Parish in Madison, Wisconsin, and the following year, as a mission preacher, he was assigned to St. Pius V Priory in Chicago. Continuing as a preacher in the western regions of the Province, he moved in1943 to Holy Name Rectory in Kansas City. He then entered the Chaplain Corps of the United States Army. Following military service, he returned to itinerant preaching in 1946, and was assigned to the "Southwestern Band" with headquarters at Holy Rosary Priory in Houston, Texas. In 1948, he changed to the "Northwestern Band" in association with the illustrious Father Vincent Ferrer Kienberger and Father David Balla, with assignment to Holy Rosary Priory in Minneapolis.

In 1951, Father Breen was appointed caput of the Northwestern Preaching Band. This assignment gave him the responsibility of "scouting" for invitations to preach parochial missions, novenas and Forty Hours devotions among the parishes and institutions of his territory; he was responsible for finding available preachers and assigning them to their missions, as well as continuing as a full-time preacher himself. This responsibility involved endless and tedious correspondence, coordinating schedules, adjusting to changes and contingencies, finding preachers for important invitations from pastors, bishops and religious superiors when there seemed to be too few preachers available. Throughout this work he was under constant pressure to serve as diplomat and public relations expert, both within the Dominican Province and in its relations with the Church of the Midwest. He was retained in this position, in various locales of the Province, for thirteen years. This testifies to his qualities of responsibility, reliability, tact and "refined good manners" that President Conry of Columbia College had pointed out in 1931.

In 1956 Father Breen moved from Minneapolis back to Chicago. Also in that year his talents and devotion to preaching, and the administration of the Province's preaching mission, were acknowledged by the Provincial Chapter: he was honored with the title and privileges of Preacher General. At that time this distinction gave him perpetual standing not only as an eminent preacher but as councilor in his Dominican community.

In 1964, when Father Gilbert Graham was elected Provincial, Father Breen stepped down from the duties of caput and continued full-time preaching from St. Anthony of Padua Priory in New Orleans, Louisiana. He was beginning to feel the wear and tear of the strenuous travel and ceaseless preaching and asked to be relieved. His request was honored in 1966 by Father Graham who wrote to him:

May I take this opportunity to express in my own name and for the Province our appreciation for the tremendous work you accomplished as a missionary and as Caput of the Mission Band for so many years. There is no Dominican in our Province who more faithfully and competently exemplified our preaching tradition throughout the Province for more than twenty-five years. Your example both to the brethren and to priests and pastors wherever you worked was always as effective a sermon as those you gave from the pulpit.

In 1967, Father Breen returned to Madison, to Blessed Sacrament Parish, which had been his first assignment in 1939. His failing health should have entitled him to complete freedom from responsibilities, but his own patience and determination won out, not only over the symptoms of disease, but overcame the greater challenges of doing nothing and consequent boredom. He adjusted to a very different style of life, cultivated a regular life of prayer and the celebration of the sacraments, a quiet but effective ministry to the Dominicans and parishioners at Blessed Sacrament. For over twenty years he became a mainstay of the Dominican community and won the affection and appreciation of the brothers who lived with him in the Priory and parishioners who counted on his prayerful presence in the church and sacristy.

In November of 1987, Father Breen moved to Nazareth House Nursing Center in Stoughton, Wisconsin, where even in illness he continued his ministry of preaching by the

example of his life until his death on October 4, 1989. Following a funeral Mass at Blessed Sacrament Church in Madison on October 7, the feast of the Holy Rosary, he was buried in the Dominican plot at Calvary Cemetery in Madison, Wisconsin,