About Us

Our Story

Most Holy Trinity Seminary was founded in 1995 in a building which it shared with Mary Help of Christians Academy in Warren, Michigan. Since it was necessary that the seminary function in its own quarters, Most Holy Trinity Seminary acquired 50 acres of land in 2003 near Brooksville, Florida, (about 50 minutes north of Tampa) with a view towards constructing a new building and relocating its operations there. Construction began in April 2005. In April of 2008, the Seminary officially opened its doors in the new facility.

Ten years later, the Seminary facility had grown too small and there was need to seek a new building with more rooms. In 2020, a suitable building was found in Reading, Pennsylvania, suitable for the needs of the Seminary and the increase in room capacity. It took over two years of remodeling and repairs to bring the building up to code. The Seminary moved into the new location in late 2022.

The Building

Our Approach

Most Holy Trinity Seminary was founded in order to provide priestly training for young men who thoroughly reject Vatican II, its reforms, and the Modernist hierarchy which promulgates them. This position is in contrast to the seminaries of traditionalist groups that operate with the approval of the Modernist hierarchy, or who seek this approval.

The Seminary trains priests according to pre-Vatican II standards. Its rule, discipline, spiritual formation, and academic curriculum imitate faithfully those which were in effect in seminaries before the Second Vatican Council. By training priests in this manner, the seminary hopes to contribute to the solution to the problem of the nearly universal disintegration of Catholic faith, morals, discipline, and liturgy  which the Second Vatican Council has caused.

The seminary sees that the only solution to the problem of Vatican II, however, is to condemn it as a false council which was dominated by heretics, and to discard and ignore its decrees and enactments. Consequently, the Seminary does not seek to be recognized by the heretical hierarchy which promulgates Vatican II, nor does it seek to work with the Novus Ordo clergy, as if in a single church or religion.

The Seminary therefore repudiates the idea of the Motu Proprio Mass, or that of a fraternity of priests which has received permission or seeks permission from the Novus Ordo hierarchy to function in communion with the Modernist heretics.

The Catholic Church, in the outlook of the Seminary, will not be cured of its current problems until the hierarchical sees, particularly the papacy, are once again occupied by Catholics. For as long as Modernist heretics possess the mere appearance of authority which they now possess, the problem of Vatican II will continue. In the meantime the Seminary, as well as the priests who emanate from it, shall abhor even the suggestion of an official recognition from the Novus Ordo hierarchy, or of a compromise with the Modernists, whom St. Pius X called the “most pernicious of all the enemies of the Church,” who are striving “utterly to subvert the very Kingdom of Christ.”


Our Seminary provides future priests with a thorough intellectual training based on the Church’s Magisterium and the Teachings of St. Thomas Aquinas. In both philosophy and theology it insists on adherence to classical Thomism.


Most Rev. Donald J. Sanborn

Founder & Rector

Nationality: American

Bishop Sanborn is currently Rector of the seminary in Reading, Pennsylvania. He also travels frequently to Mass centers in the United States, and makes occasional visits to Europe, where he meets with both clergy and lay people who share or who are interested in his uncompromising position with regard to the Novus Ordo religion.


Rev. Nicolás E. Despósito

Vice Rector

Nationalities: American, Argentinian

Father Despósito is originally from Argentina. He arrived at Most Holy Trinity Seminary in 2001. After his ordination in 2006, he stayed at the Seminary as a Professor. He currently teaches Dogmatic and Moral Theology.


Most Rev. Germán Fliess


Nationality: Argentinian

Also from Argentina, Bishop Fliess was admitted as a seminarian in 2006. He was ordained in 2010 and after the completion of his studies in 2011, he became a professor. He currently teaches Dogmatic Theology, Sacred Scripture, Latin and Greek. He was consecrated a bishop in 2022.


Rev. Luke Petrizzi


Nationality: American

Father Luke Petrizzi is from Virginia and was ordained in 2020. He currently teaches Church History and Latin. He oversees the Ceremonies and plays the organ.


Rev. Damien Dutertre


Nationality: French

Born in 1993 in Rennes, France, Father Damien Dutertre has been ordained in 2018 in Verrua Savoia, Italy. After a few years of apostolate in North America (particularly in French Canada) he is now working in Nantes, France. Besides his pastoral duties, he has continually been teaching at Most Holy Seminary, either there or remotely. He currently teaches dogmatic theology.


Rev. Tobias Bayer


Nationalities: American, Colombian

The eldest of a family of ten children, Father Bayer grew up most of his life in South America. After graduating from high school, he moved back to the USA to enter the seminary in 2015. He was ordained in Florida in 2022 and has served as Bishop Sanborn's secretary since. When needed, he serves as a substitute teacher or proctor, but most of his duties revolve around the administration and maintenance of the seminary and its missions. He occasionally makes mission trips to South America.