Primarily the first Trier bishops, Eucharius and Valerius, were venerated in this probably oldest Christian church in Germany. The present church was built in 1127. It was then that the presumed relics of the Apostle Matthias (the Apostle who replaced Judas) were found; his remains had previously been very well hidden to protect them from plundering. Since that time, the Apostle’s grave has been the goal of numerous pilgrim groups.The Holy Cross Chapel houses a Staurotheke (reliquary for a cross particle), in which a piece of Christ’s cross is enshrined. It was created after 1240, exhibiting the particle of wood. In an additional twenty small recesses, other relics have been worked in. The Staurotheke is one of the most beautiful artworks in Trier.The front of the basilica church clearly displays a long building history. The basic structure was finished about 1160. Around 1650, baroque volutes were placed on the gable, and the portals were constructed in French and Italian style at the beginning of the 18th century. The central portal shows the statues of the Apostle Matthias; the founder of the Benedictine Order, Benedict, and his sister Scholastica. The tower received its crown decoration in 1786.