DEDHAM -- The story of the Ursuline Sisters in the Archdiocese of Boston can be told by the story of a single silver ciborium.

The ciborium was created in the 18th century and was initially used by the French Navy before it was given to a Boston priest, possibly Bishop Cheverus himself. The ciborium was used in the Ursuline Convent school in Charlestown (now Somerville) before the building was burned to the ground by a mob of anti-Catholic rioters in 1834.

Two Ursuline Sisters took the tabernacle, including the ciborium, and hid it in a clump of asparagus in the garden so it would not be destroyed. Their plan worked, and the ciborium was saved. The ciborium came into the possession of Ursulines from New York, who came to Boston in the 1940s to found a girls school at the invitation of Cardinal Richard Cushing. It was the first Ursuline presence in Boston since the destruction of the convent school over 100 years prior. In 1957, the school moved to an estate in Dedham, where Ursuline Academy remains to this day. The ciborium became part of the Ursuline archives of Boston College and remained there until Oct. 18.

That day, Sister Elisa Ryan, prioress of the Ursuline Sisters of the Central Province, gave the ciborium to Head of School Kate Levesque. The handing over of the ciborium represented a larger transfer of the school's sponsorship from the Ursuline Sisters of the Central Province to the Ursuline Educational Foundation. The transition of sponsorship was marked with a ceremony and Mass in the school gym on Oct. 18, the feast of St. Ursula.

"We hope that this priceless relic from the past, from the original convent in Boston, will find a special place here," Sister Elisa said, "and will inspire and help all of you in this wonderful community to preserve the heritage of the school and to cultivate a thriving future."

The Ursuline Sisters used to be the teachers and administrators of Ursuline Academy, but a decline in vocations required leadership to be "passed on to strong, faith-filled lay leaders who have continued to carry the torch of Ursuline education," Sister Elisa said.

"We Ursuline sisters have always tried to follow St. Angela Merici's call to cultivate the vine entrusted to us and to engrave on our hearts all those whom we serve," she said. "The sisters who first arrived in Boston began nurturing and educating young women. They poured out their hearts and dedicated their lives to those in their care and built up the school to what it is today."

Despite no longer having an administrative role, the sisters had remained the sponsor of Ursuline Academy.

"Sponsorship is the call to have responsibility and to be accountable to the Catholic Church for the development and maintenance of the mission and ministry of the sponsored work," Sister Elisa explained. "Sponsorship is a way to advance the love of God manifest in Jesus and the ministry of the church."

In her remarks, Levesque thanked the Ursuline sisters for their work and service to the school.

"Today's ceremony is a symbolic capstone to years of foresight and planning on the part of the Ursuline Sisters as they endeavored to ensure the Catholic Ursuline identity of our school well into the future," she said.

Leaders of Ursuline Academy and the Ursuline Educational Foundation pledged to stay true to the school's mission and Catholic identity. The assembly, including the entire student body, raised their hands over the leaders to bless them in their future endeavors.

Mass was celebrated by Father Oscar Pratt, pastor of St. Katharine Drexel Parish in Dorchester. In his homily, Father Pratt said that the ciborium's age, material, and history are not what make it sacred, but the fact that it holds the Eucharist.

"It was created to hold what we, especially in the Catholic community, consider most holy tangibly in this world," he said, "apart from those human vessels that carry what's in it."

Like a ciborium, he said, all of the faithful carry the body of Christ within them and are a part of that body.

"When this was lost, did God cease to exist for a while?" He asked. "No. When this was no longer used, was that to say, 'Well, the Ursuline community can never celebrate the Eucharist together as family?' No, because it is a reminder of what is holy, what is worthwhile, what is everlasting, what is contained within it."

After Mass, members of the Ursuline Academy Board of Trustees were ceremonially commissioned in service to the school. Each board member lit a candle, symbolizing their commitment to the school and their "willingness to share your light with our school community," and pledged to "accept the responsibility to govern Ursuline Academy consistent with its mission and core values."

"We thank all of them for agreeing to collaboratively make and implement decisions rooted in our Catholic and Ursuline academy," Levesque said. "We offer them our prayers and support as we commission them in service to the betterment, the longevity of Ursuline Academy."

Father Pratt led a blessing of the trustees. The ceremony concluded with Ursuline Academy students and leadership signing the school's Code of Conduct.