The art essay

The Trinity Dome Mosaic (2017) by

A Christian is baptized “in the name of the Father, and of the Son, and of the Holy Spirit.” Christian faith begins, rests, and ends in the Holy Trinity. The whole Christian life aims at communion with the divine Persons. Yet for many the doctrine of the Trinity remains abstract, even removed from everyday life. One majestic mosaic depicting the Holy Trinity brings this central mystery of Christian faith to life as it offers a visual homily for the Solemnity of the Most Holy Trinity.

The Trinity Dome mosaic features fourteen million pieces of Venetian glass displayed in over one thousand color variations. The grand work spans 18,300 square feet of dome surface and weighs some twenty-four tons. Adorning the central dome of the Great Upper Church of the Basilica of the National Shrine of the Immaculate Conception in Washington, D.C., the Trinity Dome mosaic is the “crowning jewel” of this North American Marian shrine. It brings to completion original architectural and iconographic plans begun nearly a century ago as the monumental Byzantine-Romanesque basilica prepares to celebrate its one hundredth anniversary. Painstakingly handcrafted by mosaic artists in Spilimbergo, Italy, this contemporary work of sacred art invites pilgrims to contemplate anew the beauty of faith through mosaic depictions of the Holy Trinity, the Blessed Virgin Mary, the creed, a procession of angels and saints, and the four Evangelists.

Mosaics tell the story of salvation

The Catechism teaches that sacred art is true and beautiful when its form corresponds to its unique vocation to evoke and glorify the transcendent mystery of God (CCC 2502). The Trinity Dome mosaic expresses visually this vocation of sacred art to evoke and glorify God’s transcendent, Trinitarian mystery.

Four pendentives at the base of the Trinity Dome depict the four Evangelists who write their testaments under the inspiration of the Holy Spirit. Each Evangelist is shown with distinct artistic attributes following traditional iconography. The four sacred authors appear to hold up the circle, or drum, of the central dome, symbolizing the faith of the Church that rests on their sacred witness.

The Gospels, inspired by the Holy Spirit, are summarized in the words of the creed, professed by Christians universally. This link between the Gospels and the creed is conveyed visually around the dome base with the complete text of the Nicene Creed, most likely the only depiction of its kind in the world. Looking to the dome, pilgrims see the faith they profess in the creed radiating, in brilliant mosaic of gold and blue, above them—and into their hearts, minds, and lives.

As one’s gaze continues upward, larger-than-life haloed figures of God the Father, the Son, and the Holy Spirit in the form of a dove, can be seen. The love of the Trinity is evoked in their gentle expressions and gestures, inviting us to participate in the community of the divine family.

God the Father, who sits enthroned in majesty, is clothed in green and purple robes, colors indicating vitality and royalty. In his left hand, the Father holds a sphere evoking his divine, omnipotent power as Creator of heaven and earth. With his other hand he points our gaze to Jesus, his beloved Son, who sits at the Father’s right, as Scripture and the creed attest. Jesus’ left hand reaches to his heavenly Father in filial love as he holds a large cross in his right hand. The Holy Spirit, as a dove, hovers between them and radiates brilliant rays of their mutual divine love.

Across from the Holy Trinity stands the monumental figure of the Blessed Mother of God in her Immaculate Conception. Angels bear the Queen of Heaven, who is clothed in flowing robes of blue, gold, and white with a crown of twelve stars ­framing her haloed head. With her foot, she crushes the head of the ancient serpent as, with maternal eyes of love and protection, she watches over her ­spiritual children who look to her in faith. She stretches out her arms toward us in welcome. From the oculus above, golden rays bathe the entire sacred space with heavenly light.

A communion of saints adore the Holy Trinity

The closeness of the Holy Trinity to every Christian is evoked in a host of angels and saints who encircle the divine Persons. This glorious procession depicts holy angels and saints who guide a pilgrim’s journey of faith to union with the Trinitarian God. Each saint in this circular procession holds a significant place in the history of Catholicism in the Americas, such as Saint Juan Diego with his tilma image of Our Lady of Guadalupe, Saint Elizabeth Ann Seton, Saint Junípero Serra, Saint Kateri Tekakwitha, Saint Damien of Moloka’i, and Saint John Neumann, among many other saints framed on either side by the Archangel Michael and the Archangel Gabriel. The faithful who gaze on this heavenly procession are invited to join in their hymn of adoration and praise to the Father, the Son, and the Holy Spirit.

Communion with the Triune God

In this Marian shrine, known affectionately as “Mary’s House,” sacred art invites pilgrims to walk with the Mother of God as she points to her divine Son Jesus who leads them to the Father in the power of the Holy Spirit. Sacred art serves to illustrate the origin and goal of the Christian life which is union with the Triune God in faith, love, and service of neighbor.

Notable pilgrims to this Marian shrine include Saint John Paul II, Pope Benedict XVI, Pope Francis, and Saint Mother Teresa of Calcutta, among others. The Trinity Dome mosaic invites all the faithful to draw close to the Holy Trinity by contemplating this work of “genuine sacred art that draws us to adoration, to prayer, and to the love of God, Creator and Savior, the Holy One and Sanctifier” (CCC 2502).

Jem Sullivan

Educator, author, and writer on sacred art and faith in the New Evangelization


The Trinity Dome Mosaic (2017), Basilica of the National Shrine of the Immaculate Conception, Washington, D.C. © Basilica of the National Shrine of the Immaculate Conception, Washington DC.