The Cathedral, formerly the collegiate parish Church of Our Lady of Adoration, has remained unfinished. On the site of the current church once stood a 12th century Romanesque church which itself was preceded by two earlier churches. Construction of the choir of a new church began in 1230.
The building plans were changed a number of times, as is apparent when observing the variety of styles from early to late Gothic. After only partial completion of the splendid south tower and west facade, construction came to a halt due to lack of funds. Of the many stone carvings and statues planned for the outside walls, only a modest portion was completed. The Romanesque west front and north tower, known as the Heidenturm or “Heathen Tower,” were left standing and are an integral part of the current church structure.
Entrance to the church is through the early Gothic south portal. Very little of the original interior has survived other than the Romanesque font from the earlier church, a large, late 14th-century Pietá, two depictions of the Mother of God on a crescent moon and other figurines from the late Middle Ages. There are a number of interior details such as the pulpit and the Baroque tombstones which date from the time of the Imperial Chamber of Justice.
The church has been used concurrently by both Protestant and Catholic congregations since the Reformation.
The convent, founded in the 10th century, found that there was a church building already available to them. Several sources, albeit long after the event, document the year 897 as the date of consecration. It was found necessary to reconstruct the eastern part of the building in 1000. The second period of reconstruction, which utterly changed the appearance of the church, was between 1170 and 1190.
The late Romanesque collegiate church was only about 40 years old when in 1230 the decision was taken to replace it with a considerably larger building. A comparison with the neighbourhood might well have prompted this course of action. The collegiate church of St. George in Limburg, begun in 1215, was already almost completed; and after the canonisation in 1234 of Elisabeth of Thuringia, who had died in 1231, Marburg immediately started building a church over her grave in the early Gothic style, a style which was still unusual in Germany.
The plans included three naves, a transept and a choir and the intention was to make the church clearly visible from afar. It would indeed have been a striking landmark in the centre of the Lahn valley with two impressive towers with openwork spires. But the course of history took a different turn.
Even from a distance, the cathedral presents an unusual picture. A tower and exterior of red sandstone, plastered walls and occasional patches of the underlying greenstone (Schalstein) defy uniformity. A closer look at the Wetzlar cathedral will confirm its uniqueness.
The facade was never completed. The left tower was never built and there is only a plinth to indicate that it had been planned. A large centre portal exists, but there are no steps leading up to it. The west wall does not lead into the nave but to an empty space. Beyond it is another facade heavy, squat, dark grey and quite out of keeping with the slender, soaring, filigree style of the surrounding Gothic architecture. It is the remains of the late Romanesque basilica which the convent and the town had wanted to demolish to make way for a more impressive new building. It was knocked down bit by bit while the new church was being constructed so that the church could remain at least partly functional throughout the period of building.
Who at that time could have guessed that Wetzlar and the convent would argue over financing building costs, that there would be a catastrophic financial and economic crisis towards the end of the 14th century culminating in the towns bankruptcy? The result was delays in building the church and there were decades where no progress was made at all.
Masons lodges came and went with the numerous delays and periodic resumption of work, meaning that there were many different influences on the architecture of the church not only different styles and building techniques, but even completely new plans for the building as a whole. Of the two towers planned, one was built and received its wooden spire about 1490, but then work ceased. Lightning struck and destroyed the spire in 1561. The hood-like roof as we now know it was built in 1590. Its style takes leave of the Renaissance and embraces the coming Baroque period. The Wetzlar cathedral bears the hallmark of every style of ecclesiastical architecture from the late Romanesque to the Baroque period a potted architectural history spanning four centuries!
The Reformation brought the Lutheran faith to Wetzlar and from then on the church was shared. To this day, two parishes Catholic and Protestant use the same altar and the same organ, donated, incidentally, by the industrialist family, Leitz.