The small Romanesque church is the oldest building of the entire Castle grounds. It was built together with the Romanesque fortress and consecrated in 1187. Later, the chapel received a Gothic extension. In 1890, linear Gothic frescoes from the first half of the 14^th century were discovered on the church walls. Tombstones of members of the Zapský family, the original 16^th century owners of the Průhonice manor, are placed in the external walls of the Church.