The church of St. Lubentius rises from a rocky bluff overlooking fields of wheat, the River Lahn and the village of Dietkirchen. The bluff has been inhabited since the Neolithic era. A church may have existed on the site since the 4th century. The first stone church was built about the year 730. A monastery was established by the 9th century. The church was rebuilt about 1000 and again in the 11th century when the current floor plan was established. There have been several renovations since then.
From the nave several generations of construction can be distinguished. The side aisles were groin vaulted in the 12th century. The galleries above were enlarged at about the same time, the arches were filled in with the slender middle columns in the 13th, reopened in the 19th century and restored to the 13th century configuration in the 1960s. The Choir and crossing were expanded and ribs were added to their existing groin vaults.
The low groin vaulted side aisles held numerous altars that were used by priests from the adjacent monastery, which was destroyed in 1640. Later that century the altars were removed.
A small chapel in the back of the church holds the reputed relics of St. Lubentius. He was a priest in Koburn, a town on the Mosel River to the west, who died about 370. He is not known to have been to Dietkirchen, but his bones were probably sent there no later than 841. The gold bust in the case on the altar contains his skull. The casket beneath holds the rest of his bones.