In the years since its 1959 dedication, the Basilica of the National Shrine of the Immaculate Conception has had three main architectural focal points: on the exterior, its Great Dome and Knights Tower over the northeast Washington skyline, and in the interior, its dramatic Christ in Majesty mosaic behind the main altar.

With the Dec. 8, 2017 dedication of its interior Trinity Dome Mosaic completing its original architectural and iconographic plans, the basilica has a new dramatic focal point, before it marks the centennial of the laying of its foundation stone in 2020. And Msgr. Walter Rossi, the National Shrine’s rector, said in an interview that it is fitting that the Trinity Dome is centrally located in the nation’s largest Catholic church and central to the new mosaic’s iconography.

“The Trinity is central to the mosaic, because the Trinity is central to our Christian life and faith. This is how God has revealed himself to us as Father, Son and Spirit,” Msgr. Rossi said.

Opposite the monumental figures of the Trinity in the mosaic is a nearly three-story high depiction of Mary as the Immaculate Conception, appearing as a beautiful young woman, her arms extended toward a procession of saints and holy people, ultimately pointing to her son Jesus.

“Mary’s arms are outstretched to embrace us, just as the arms of Jesus in Christ in Majesty are outstretched to embrace us,” the rector said.

He noted that those two main parts of the Trinity Dome mosaic are based on 1953 designs by the shrine’s iconography committee as plans were underway to complete the Great Upper Church.

“We altered the figures on the east and west sides to include saints of the United States, and saints who had a history with the National Shrine, like Mother Teresa and St. John Paul II, and we also wanted saints that reflect the face of the people who come here,” said Msgr. Rossi.

That procession of saints reflects the diversity of the nearly one million pilgrims from across the United States and from around the world who come to pray at the basilica each year.

“This without question is the most diverse Catholic church in the United States,” the National Shrine’s rector said, noting that is why the saints in the mosaic include St. Juan Diego from Mexico, St. Lorenzo Ruiz from the Philippines, St. Josephine Bakhita from Sudan in Africa, and St. Kateri Tekakwitha, the first Native American to be recognized as a saint.

Those holy people depicted in the mosaic include St. John Paul II, who in 1979 became the first pope to visit the National Shrine, where he prayed in the Our Lady of Czestochowa Chapel and addressed a gathering of women religious. Also pictured is St. Teresa of Calcutta, who visited and prayed at the basilica many times over the years.

The saint in the mosaic with the most recent connection to the National Shrine is St. Junípero Serra, the noted 18th century Spanish Franciscan missionary of California who was canonized a saint in 2015 by Pope Francis in a Canonization Mass outside the basilica, the first sainthood ceremony held in the United States.

In addition to St. John Paul II, the saints in the mosaic include two other popes: St. John XXIII who was pontiff when the National Shrine was dedicated in 1959, and Blessed Paul VI who visited the shrine one year later as a cardinal.

“The popes have been a part of the shrine since the very beginning, when Pope Pius X in 1913 gave permission for the shrine to be built, and the continued connection with popes throughout the decades shows the significance of this Marian shrine in the life of faith for United States Catholics and for Catholics throughout the world,” said Msgr. Rossi.

The rector noted that it was also fitting to have the text of the Nicene Creed encircling the base of the Trinity Dome.

“The original concept was to have the Athanasian Creed which most folks wouldn’t know. We thought it would be more appropriate to have the Nicene Creed which we pray at Mass. As you read this Creed, it’s a summary of what we believe and profess. It’s fitting the Creed surrounds the base, because it’s the Creed which surrounds our life of faith,” the priest said.

The pendentives – the triangular sections of vaulting on four corners of base of the dome – depict the four evangelists, St. Matthew, St. Mark, St. Luke and St. John, who brought the Gospel of Jesus to the world. Msgr. Rossi noted that each evangelist holds a scroll bearing a few words that summarizes what their Gospel focuses on.

The Trinity Dome mosaic’s figures, symbols and words all together offer a visual representation of the Catholic faith, the priest said.

“That’s what religious art is meant to be, a catechism… Looking at religious art, people learn about the Gospel message, the lives of the saints and salvation history,” he said.

Msgr. Rossi – a 56-year-old priest of the Diocese of Scranton, Pennsylvania, who became the basilica’s rector in 2005 – said what inspires him most at the National Shrine is witnessing the faith of the people who come to pray and worship God there. Now in his 20th year at the basilica, he served as the director of pilgrimages there for eight years before becoming rector.

The priest said that when he became rector, he had it in mind for the Trinity Dome to be completed in the years ahead, perhaps before the 2020 celebration of the basilica’s centennial. “We gradually kept moving forward,” he said, noting installation and dedication of the basilica’s Redemption Dome in 2006 and its Knights of Columbus Incarnation Dome the following year.

About three years ago, work on the Trinity Dome moved forward, from the design stage to the fabrication of the mosaics in Italy, to the construction of scaffolding that rose 16 stories from the basilica’s floor, to the installation of the mosaic on the Trinity Dome.

“This is one of the largest mosaic domes in the world,” said the priest, who noted that he made several trips to the Travisanutto mosaic studio in Spilimbergo, Italy, to inspect the work as it was being fabricated.

“This is made by hand. Going to the factory, I watched them make it by hand,” said Msgr. Rossi. “This is a work where every one of almost 15 million pieces of mosaic tesserae (Venetian colored glass) are not only put in by hand with tweezers, they are cut by hand to fit in the space. The people who do this have great patience.”

The National Shrine’s rector noted that the workers at every step of the process demonstrated that they knew they were helping to create something special, a work of art and a work of faith that would inspire generations of pilgrims coming to pray at the basilica.

“Every person who was involved with this project, from the artists who came up with the ‘cartoons’ (sketches) of the images, to the people who fabricated the mosaic and installed it, to all those who worked to design and build the scaffolding, every one of those people knew how important this project was, and when we would visit with them, going up to the mosaic to inspect the work, you could see how proud they were of this work,” he said.

Washington Cardinal Donald Wuerl and Msgr. Rossi celebrated a Mass in Italy for the mosaic workers and blessed their work, and in October 2016 after the scaffolding was built at the basilica, the cardinal blessed the Trinity Dome before the mosaic was installed.

“Cardinal Wuerl blessed the work space and the workers. Regardless of their faith, the workers all came to the cardinal for an individual blessing,” the rector said.

For Msgr. Rossi, a special climax of the whole process came about two months later. “The most emotional part of this for me was the day in January (2017) when I went up to the top of the scaffolding with the mosaicists, and we put in the first piece of the mosaic, which was the symbol of the evangelist St. Luke,” he said. “Father (Michael) Weston (the basilica’s director of liturgy) and I went up together. Mosaicists put the mosaic in, and Father Weston and I pulled the paper off to reveal the mosaic. That moment really made this a reality. That’s an emotional moment – knowing it’s actually happening, it’s coming to fruition.”

The priest also expressed appreciation for the other “builders” of the National Shrine – the nation’s Catholics who have supported it from the beginning and continue to support it.

“It’s important to note that the National Shrine was built because of the generosity and prayers of U.S. Catholics… (and) we keep our doors open because of their goodness today,” said Msgr. Rossi, who noted that under one of the Trinity Dome windows, letters formed in mosaic tiles ask for prayers for the dome’s benefactors.

Praising the generous response to the nationwide collection on Mother’s Day to complete the Trinity Dome, the rector said, “The Mother’s Day collection was an expression once again of how important this place is to Catholics in the United States, that by asking people to make a gift to their heavenly mother on Mother’s Day, they showed once again that Mary’s shrine is a significant place in their life of faith.”

The Dec. 8 dedication of the Trinity Dome will also mark a special homecoming, as Cardinal Kevin Farrell, the prefect of the Vatican’s Dicastery for Laity, Family and Life, will return to Washington to serve as the envoy for Pope Francis at the Mass.

Msgr. Rossi noted, “It’s extraordinarily meaningful, because Cardinal Farrell was a priest of Washington, ordained as a bishop in this Upper Church, as bishop of Dallas was a member of the Board of Trustees and served on our finance committee. He’s always been a great supporter of our ministry and a good friend to us.”

When asked what impact he hopes that the Trinity Dome Mosaic will have on visitors to the National Shrine, the priest said, “As you look up and see the images of the Holy Trinity and the Blessed Virgin Mary, you cannot but be reminded that the goal of our life on Earth is our life with God, that heaven is our final goal, to rejoice forever with Mary in a hymn of praise to the Blessed Trinity, and then we have the saints whose lives and example direct us on our way. Everybody’s life is a pilgrimage to the Father.”