Boppard - Early christian church

Forming the town centre of Boppard are the impressive ramparts of a late Roman fort. Here, on the Rhine, during the first half of the 4th century, a Roman military unit was garrisoned.
The baths were an indispensable part of Roman life. An approximately 50m long bathing complex stretched alongside the fortress wall.
The many rooms, which included the changing rooms, the thermal bath and the hot and cold baths, give an impression of the Roman bathing process.
There is nothing left of the baths today but in the Boppard museum a model of the whole complex can be viewed.  The thermae were in use until the end of the Roman occupation of the Middle Rhine area that is up to the beginning of the 5th century.
In 406 the Roman troops left the fortress and it became a civic settlement. Evidence of Christian communities are found preserved in surprisingly many late Roman forts.  The early Christian churches were located inside the old fortress walls; they temporarily fulfilled military purposes and religious services were held there for the fort inhabitants.
During archaeological excavations inside the Boppard church of St. Severus the foundations of the Roman fort, the  baths  and an early Christian church were revealed.
After the withdrawal of the military units the civilian population inhabited the fort area and converted it according to their needs.  During the second half of the 5th century an early Christian church arose which stood until the 8th century when it was replaced by a new construction.
The earliest church in Boppard was constructed by converting the large gymnasium of the bath complex into a one bay church, which measured 32 metres in length.
The semicircular East wall of the Roman bath was neatly adapted to become the semicircular end, the apse, of the church choir.
The fortress wall itself became the Northern wall, and limit, of the church construction.
On the South side of the church four rooms of the thermae were integrated into the new construction. Of these, the room next to the choir probably served as some sort of sacristy, while the others served, probably, as storage areas.
From the slightly elevated choir a 6 m long and 1,4 m wide bordered walkway, also known by the name Ambo, led to the nave and ended in the round pulpit-shaped extension. The pulpit was not only used for annunciation but also for the introduction of the newly baptized into the community.
In the West part of the church, in a smaller room, a baptismal font was located.
Steps led down to the 1,3 m wide font, which, when filled would have been approximately knee-deep with water. The baptism was performed by pouring water over the head, the so-called aspersion. A kind of canopy of state covered the font. Comparable constructions are found in precursor buildings such as the Liebfrauenkirche in Treves or the Bishops Church of St. Ursula in Cologne.
Because of the font located inside the church the building can be unambiguously defined as a baptistery. Some of the original archaeological findings can still be seen in the church of St. Severus. The course of the Ambo is visible on the floor of the middle bay; the original font is located in a room beneath the church floor.

[Martin Thoma]