and employs Borromini-like forms. In the dome, there is an opening or oculus from which four putti emerge to carry a central tempietto, all of which frames a light-filled chamber above, illuminated by windows not visible from below. Complexively, four different types of direct and indirect lighting are placed into the borders of a small space of a "pre-built side-chapel facing south along the left side-aisle of the medieval church", producing a unique "instance of the scenic use of light in baroque architecture." The church keeps a relic of Saint Apollonia, her head, as well as a portion of the Holy Sponge. Among those buried in the church are Pope Callixtus I, Pope Innocent II, Antipope Anacletus II, Cardinal Philippe of Alençon and Cardinal Lorenzo Campeggio. The titulus Ancient sources maintain that the titulus S. Mariae was established by Pope Alexander I around 112. Later traditions give the names of the early patrons of the tituli and have retrospectively assigned them the title of cardinal: thus at that time, the cardinal-patron of this basilica, these traditions assert, would have been Calepodius. Pope Callixtus I confirmed the titulus in 221; to honor him it was changed into Ss. Callisti et Iuliani; it was renamed S. Mariae trans Tiberim by Innocent II. By the 12th century, cardinal deacons as well as the presbyters had long been dispensed from personal service at the tituli. Among the past cardinal priests holding the honorary titulus of Santa Maria in Trastevere have been James Gibbons, Pope Leo XII, Józef Glemp, and Cardinal Henry Benedict Stuart, whose coat of arms, topped by a crown (some hailed him as King Henry IX of England) rather than a galero (red hat), is visible over the screen to the right of the altar. The incumbent titular holder is Carlos Osoro Sierra Archbishop of Madrid since November 19, 2016 upon the death of Loris Francesco Capovilla, the oldest living cardinal at the time of his death on 26 May 2016. Significant events In July 2014, the wedding of Prince Amedeo of Belgium, Archduke of Austria-Este, and Elisabetta Rosboch von Wolkenstein was held at the basilica. See also Roman Catholic Marian churches Fountain in Piazza Santa Maria in Trastevere References External links "Titulus" article, Catholic Encyclopedia (1908) "Roman Monographies: Fountains Part III" Fountain in Piazza Santa Maria in Trastevere "Church Location on the Map and more info" "3D model of the balisica