A medieval abbey church, Roman trading warehouses, perhaps also a sports venue with pool, and a post-war ruin are all part of the story of the Cologne church Gross (Great) St Martin.

Visitors to Gross St Martin get two historical sites in one – a fascinating church from the High Middle Ages and a Roman archaeological site.

This prominent church, squeezed between Alter Markt and Fischmarkt, suffered under World War II bombing. It was reduced to a ruined shell, which demanded extensive rebuilding but also excavation, which revealed its important role in Cologne’s Roman past.

Roman structures from the 1st and 2nd centuries CE were found underneath the church.

On top were 11th and 12th century churches, the later with the trefoil-shaped choir and apse known Cologne’s other medieval Romanesque churches.

Cologne’s medieval story resurrected

A cloister from the Benedictine abbey on the north side and a small parish church called St Brigid on the south side have vanished. But its memory is honoured by a tiny chapel on the south wall now called the Brigidenkapelle. It contains a sculpture of the Irish saint and an intriguing (but damaged) 19th century mosaic floor showing the seven fat cows.

A church mentioned in written records is believed to have existed in the 10th century, along with a monastery. After the 1150 Cologne city fire, work on the present church began and a consecration was held in 1172, although building work probably did not end until 1250.

The reconstructed church today reflects the Rhine regional version of Romanesque architecture, despite changes in the Baroque period and after. A powerful main tower that stretches 75m high, with four hexagonal corner turrets, dwarfs the nave. Compare this to the nave length of 55m.

In the interior of the nave, there are three levels. At ground level, large arches divide the centre aisle from the two side-aisles. Above this are blind, slightly pointed arcades – designed to look like gallery features known as triforia – divided by three larger pointed arches on each side, stretching above to enclose the upper windows and form the nave cross-vaults. Otherwise, the inventory of today’s church is spare.

The mosaic paving under the crossing shows images of the Eight Beatitudes, as taught by Christ, personified.

The ornate 13th century limestone baptismal font remains, along with a group of precious Gothic carvings attributed to the workshop of the master sculptor Tilman Heysacker, who was active about 1500. Christ on the Cross, with Mary and John beneath, are matched by a scene at the holy grave in a niche below.

The crossing tower was rebuilt in the 1960s. Extensive excavations carried out in the 1970s uncovered the earlier Roman remains. The fully rebuilt church opened in mid-1980s.

Roman past under a Romanesque church

The Fischmarkt precinct was in Roman times towards the northern end of a narrow, 1km long island in the Rhine. This made it ideal for port infrastructure.

Four large warehouses, surrounding a courtyard on three sides, formed part of the port complex. Today’s church was built above
the smallest of these, using two walls as nave foundations, which
means the dimensions of this large church were likely dictated by the Roman building.

The Roman levels under the church were unearthed by excavations carried out under the bomb-wrecked church after World War II. For this reason historians know a good deal about the site, as well as Roman trading operations. Visitors can see the results by taking the stairs in the north aisle to the subterranean level.

Parts of the excavations now on display include parts of a still mysterious water basin – which has been speculated as a pool that was part of a sports complex or maybe a tank to keep fish fresh – and the former courtyard walls, remains of pillars and the outer walls of the warehouses.

The Romans closed the port about 100CE and the narrow arm of the Rhine around the island was gradually filled in with refuse and industrial waste over centuries. The result is that the Rhine bank today is further east than it was in Roman times, demonstrated by the difference between it and the Roman city’s east wall.

Visiting Gross St Martin

The church is open to visitors restricted hours on Sunday. It is next to the reconstructed medieval square Fischmarkt and close to both the centre of Cologne and transport.

For all the details of visiting times and transport links, download Raven Guides’ Cologne guide or any of the other detailed German city guides. Explore more European travel tips at the website.

For more on Cologne’s fascinating history, check out the blog on Cologne’s cathedral, Dom St Peter and the mysterious Basilika St Ursula church, with its own Roman connection.