With over 1.25 million pieces of glass, the resplendent Sanctification Dome mosaic covers a staggering 3,950 sq. feet and features 2,500 different colors – including 50 unique shades of gold. Also known as the Descent of the Holy Spirit Dome, it is one of the five distinctive domes located in the Basilica’s Great Upper Church. It was designed by Max Ingrand and dedicated in 1968, making it the second oldest dome in the Basilica.
The Descent of the Holy Spirit
The Sanctification Dome depicts the events of Pentecost as detailed in Acts 2:2-4, when the Holy Spirit came to the disciples:
“And suddenly there came from the sky a noise like a strong driving wind, and it filled the entire house in which they were. Then there appeared to them tongues as of fire, which parted and came to rest on each one of them. And they were all filled with the Holy Spirit and began to speak in different tongues, as the Spirit enabled them to proclaim.” Acts 2:2-4
The dome portrays the vivid imagery of this passage in brilliant mosaic detail, with dozens of bright red “tongues of fire” descending upon Mary and the Apostles. The miracle of Pentecost marked the fulfillment of Christ’s promise to His followers in John 14:16 – “And I will ask the Father, and he will give you another advocate to help you and be with you forever.”
The Sanctification of the World
With the descent of the Holy Spirit, the disciples were equipped to share the truth of Christ’s sacrifice with people of diverse backgrounds. In addition to Mary and the Apostles, the mosaic also features ordinary men, women, and children being anointed with the Spirit. The four pendentives include people from Asia, Africa, Europe, and America, symbolizing the sanctification of the entire world by the Spirit, regardless of gender, age, or race. The imagery reminds us that any person who chooses to repent and be baptized “will receive the gift of the Holy Spirit.” (Acts 2:38)
The descent of the Holy Spirit is also interpreted in the stained glass of the Trinity Dome windows, the Glorious Mysteries Chapels of the Great Upper Church, and in the Rosary Walk and Garden.
See the Dome Virtually
You can enjoy immersive 360° views of the dome below with our virtual tour.
Basilica Guide and Tour Book, Dr. Geraldine Rohling