July 7, 2007 Pope Benedict XIV issued the Motu proprio, the Apostolic letter Summorum Pontificum, recognizing that the Traditional Latin Mass had never been abrogated, and widening its availability to priests and lay faithful. The Holy Father defined two forms for the rule of prayer in the liturgy of the Latin, or Western Rite of the Catholic Church: the Ordinary Form as contained in the Missal of Pope Paul VI, and the Extraordinary Form, the traditional Latin Mass as promulgated in the Missale Romanum of Pope Saint John XXIII in 1062.
In light of the prescriptions of Summorum Pontificum, in December 2007 His Excellency Bishop Kevin C. Rhoades established Mater Dei Community to serve as a home for the Traditional Latin Mass in the Diocese of Harrisburg.
The Mater Dei Community has the use of the historic St. Lawrence Chapel in downtown Harrisburg. Bishop Rhoades also appointed a full-time chaplain, assigned from the Priestly Fraternity of St. Peter, to provide for the pastoral needs of the Mater Dei Community. With the ministry of this chaplain, the Community has the offering of the Holy Sacrifice of the Mass on a daily basis, as well as the celebration of all the sacraments and the other rites of the Church according to the Missal and ritual books of Pope Saint John XXII.
Mater Dei Community continues to grow and now has two full-time chaplains assigned from the Priestly Fraternity of St. Peter (FSSP).