As a bishop, Servatius may have been the founder of several early Christian churches in the diocese of Tongeren. Two likely candidates are the Basilica of Our Lady in Tongeren and the Basilica of Our Lady in Maastricht. In the case of Tongeren, this traditional claim was supported by excavations in the 1980s, which revealed under the medieval church remains of a 4th-century church, possibly the original cathedral of the diocese. The origins of the Maastricht church of Our Lady remain uncertain, since no excavations have ever been carried out inside this church. In another Maastricht church however, the Basilica of Saint Servatius, excavations in the 1990s have revealed the remains of a 6th-century church (built by bishop Monulph and described by Gregory of Tours as a "magnum templum"), with at its center a late Roman structure, possibly the tomb of Servatius.