The Baroque church on the premises of the Clementinum was commissioned by the Jesuits and built by the architect Antonio Lurago between 1711 and 1715. The simple exterior opens to reveal an elaborate interior. Of special value are the sculptures by Matthias Braun on the six side altars, and a painting by Petr Brandl. The Greek Catholic Church uses the church for masses in Old Church Slavonic and Ukrainian.
The cathedral of St Clement is one of three churches at the Clementinum. Part of the church stands at the site of the Romanesque Church of St Clement which had belonged to the Order of Dominicans. The new and, from the outside, simple Baroque building was constructed by Anselmo Lurago according to plans designed by architect Franciscus Maxmilian Kaňka in 1711 – 1715.
One of the most beautifully decorated Baroque interiors in Prague is inside this church. The simple exterior of the church makes the interior even more outstanding. The single nave church has six side altars. Major Baroque artists of the time contributed to the intricate decor. Decorative stucco work was created by S. Götzler in 1715. Johann Hiebl’s original frescoes depicting scenes from the lift of St Clement have been preserved in individual sections of the vaulting.
The stone statues of the church fathers and evangelists are the work of Matthias Bernard Braun, as are the sculptures in the side altars and the pulpit. Underneath the choir loft are the confessionals; the meticulous wood carvings are again the work of Matthias Braun.
The trompe-l’œil main altar is dominated by a painting of Saint Clement and a painting of Saint Ignatius of Loyola. On the side St Lawrence and Leonard altar is a Peter Brandl painting depicting Saint Leonard healing the sick. Ignaz Raab also contributed to painting the interior, creating paintings of Jesuit saints and Bohemian patrons in the alcoves and on the pilasters. The richly decorated pews are also worthy of note. The floor tiles are made of colourful marble. The acoustics inside the church are outstanding.
The church was given to the Greek Catholic Church in 1931. In 1950 – 1969 it belonged to the Orthodox Church, but since 1969 it has again served the Greek Catholic Church. Services are also held in Ukrainian and Church Slavonic.
Source: https://www.prague.eu/en/object/places/453/cathedral-of-st-clement-katedrala-sv-klimenta