St Francis of Assisi Church
(Krizovnicke namesti Square)
The architect Jean Baptist Mathey designed the very significant architecture of St Francis of Assisi Church for John Frederick of Wallenstein, the Archbishop and superior of the order of Knights of the Cross with the Red Star. The church was built during the years 1679 to 1685 and had been successively furnished with movables and artworks until the half of the 20th of the 18th century.
The Archbishop's intention was to build a church in Prague, accordant with the Roman architecture of that time. No architect in Prague was able to carry out such a task though. That is why the official Wallenstein's court painter Mathey performed the task. As we can now realize not only from the St Francis Church itself, but also from number of other Mathey's buildings, it was definitely a lucky choice. Although Mathey had probably no direct experience of designing buildings, we can still consider him as a very erudite expert in Roman architecture.
As evidenced by archival sources, just this man most probably became a teacher of Jan Santini Aichel. We know that Santini, much like Mathey, was not allowed to perform buildings himself because he was not member of masonry guild. That is why he had to commit these projects to skilled master builders. Of course, he neither could train the apprentices in buildings. Nevertheless, as a skilled painter, he could theoretically provide training in painting. That is most probably the reason why Jan Santini was officially not an architect but a skilled painter, too.
The architecture of the Church of the Knights of the Cross does not very much remind of Santini's implementations at first sight. While Santini fairly abounded with his own architectural ideas, Mathey more likely just works with the chosen Roman themes and motifs with sophisticated knowledge. Nevertheless, closeness of the approach of both architects is major than evident at the first glance. First of all, they both perfectly manage work with classical order architecture, composition of buildings volume, façade schemes as well as masterful creation of spaces. Both Santini and Mathey also understand work with the light very well. Not by chance, architectural approach of the Baroque at its peak is often called “sculptural” or “painter's” one. In Rome, quite a number of significant architects had different than architectural education initially, too (painters, sculptors, stucco workers).
Further point of concurrence is using ground plan with iconographic significance – a Cross in this case - referencing to the titular Saint Francis and his mystical experience when the Holy Cross carried by angels is revealing to him.
The Christian Cross is also the main motif of artistic decoration of the church, permeating in various coherences for example the themes of the individual altar canvas paintings.