FENWAY PARK -- An estimated 20,000 people filled the seats between home plate and Pesky's Pole at Fenway Park Sept. 15 to participate in the Mass of the Holy Spirit celebrated to commemorate 150 years of Catholic education at Boston College and Boston College High School.

Students, faculty, staff, alumni, and their families from both institutions joined in the Mass to kick off three semesters of Sesquicentennial Celebration, with the liturgy traditionally celebrated by Catholic academic institutions at the start of every school year.

"It is a grand manifestation I think of the spirit of loyalty and commitment of Boston College and Boston College High School alumni. You look around and see all the people who are here, priests, lay men and women. I think there is a common bond that we all share, a faith tradition and a commitment to community that manifests itself in all of the people who are present," Boston College president Father William P. Leahy, SJ, said.

Staff, trustees and faculty of both institutions processed into the stadium behind a liturgical cross dating back to the founding of Boston College in 1863, a symbol of the heritage shared by the university and the high school.

In the first 50 years since Father John McElroy, SJ, founded the Catholic educational institution, the university and the high school remained one Jesuit school. In 1913 Boston College relocated to its present site in Chestnut Hill as enrollment swelled. The two shared one administration until they separated in 1927, becoming two distinct institutions.

Boston College developed into a university, as it was originally incorporated, expanding graduate studies from the 1920s through the 1940s, and opening the first residence halls in the 1950s. At that point, the university began a transition to a modern university by welcoming women into studies for the first time.

The campus in Brighton became home to the School of Theology and Ministry in 2008.

Today, the university confers more than 4,000 degrees in roughly 50 fields, as an internationally recognized leader in Jesuit education.

Nearly one hundred Jesuit and alumni priests concelebrated the Mass with principal celebrant Father Leahy. Cardinal Seán P. O'Malley presided at the Mass and was joined in choir by Bishop John A. Dooher and Manchester Bishop Peter Libasci.

"Today we begin the celebration of the 150th anniversary of Boston College and Boston College High School, started in 1863. In the midst of the civil war, the decision was that there was a need for a school largely for the Irish immigrants in the Boston area. Today here at Fenway Park where a lot of Bostonians have worshiped in another way, we are together to celebrate God's goodness to the society," Jesuit New England provincial Father Myles Sheehan told The Pilot.

Father Michael Himes, a theology professor at B.C., said he felt surprised when he was invited to deliver the homily despite not being a Jesuit. Nevertheless he demonstrated his understanding of the teachings of St. Ignatius of Loyola in a Catholic context of education.

"What you hold on to you lose. What you give away you can never run out of," Father Michael Himes said. "Let me suggest to you that that applies to our education as well."

"The reason to be educated is to teach somebody else. You never fully grasp the fruits of your education until you give it away," he said.

Cardinal Seán P. O'Malley gave delivered remarks before the final blessing.

He thanking Father Himes for his homily, he said, "Father you hit it right out of the park. The Boston Red Sox should get you."

The cardinal praised the virtue of the two Jesuit educational institutions in their years of service to the archdiocese.

"The Church's vision is to pass on the Catholic faith and to serve the whole community through our parishes, our schools, social services, healthcare institutions and B.C. High and Boston College have been a very important part in the history of our local Church, and we are all delighted to be a part of this magnificent celebration here in Fenway park," he said.

The Mass formally launched the university's Sesquicentennial Celebration, concluding in November 2013, that will feature six academic symposia; a sesquicentennial speakers series; a founder's day celebration; a student concert at Symphony Hall; a convocation of Catholic college presidents; a service program in which each B.C. student and alumnus will be asked to perform 150 minutes of volunteer community service; and the release of a GPS-guided campus tour app called "Tour of the Heights," two books and a documentary, among other events listed at www.bc.edu/150.