The church began at the time of Otto III (980-1002), probably as compensation for shifting of the bodies of the martyred saints to Rome, and underwent changes until the fourteenth century. The church is made of brick interposed with early medieval marble while the apse is tuff. The bell tower has three floors with mullioned windows and was built using the buttress of the church. The interior is divided into bays by pointed arches and elevated in the presbytery are a table and a stone seat. In the trapezoidal crypt a particularly beautiful fresco can be found: St. Michael with his face very realistic, suggesting the idea of the third dimension, and with shining white wings that make the idea of an angel as "hierarchically" closer to God. The apse is painted with a scene of the Apocalypse, the Holy Family and the Day of Judgement, a typical medieval scene with educational purposes for the faithful to bring them closer to God, but also to control them. These scenes were the Bible of the poor and illiterate.