Begun in 1248, the construction of this Gothic masterpiece took place in several stages and was not completed until 1880. Over seven centuries, successive builders were inspired by the same faith and a spirit of absolute fidelity to the original plans. Apart from its exceptional intrinsic value and the artistic masterpieces it contains, Cologne Cathedral testifies to the enduring strength of European Christianity.
Christians met for worship in a private house in the north-east quarter of Roman Cologne near the city wall. Following the Edict of Milan in AD 313, when Constantine proclaimed religious freedom, this building was enlarged as a church. Alongside it were an atrium, a baptistery, and a dwelling-house, possibly for the bishop. This modest ensemble was extended and enlarged in the following centuries.
Credit for inspiring the construction of the first great Romanesque cathedral on the site is given to Archbishop Hildebold, a friend and advisor of Charlemagne. This immense building, known by the 13th century as "the mother and master of all churches in Germany; was consecrated by Archbishop Willibert in September 870. Post-world war II excavations, as well as contemporary documents, provide evidence of its form and decoration. It was a basilica, with a central nave flanked by two aisles, c. 95 m in length (two further flanking aisles were added in the mid-10th century, making it the first five-aisled church outside Rome) and with a large atrium in front of its western facade. A two-storeyed Chapel of the Palatinate, in the style of Charlemagne's chapel in Aachen, was added to the south transept at the beginning of the 11th century, and in the second half of that century it was connected by two lofty arcades at the east end with the Collegiate Church of St Mary ad Gradus.
Despite its generous dimensions, this cathedral was found to be too small to accommodate the throngs of pilgrims who visited it after the relics of the Magi were brought there from Milan in 1164 by Archbishop Reinald von Dassel. The ambition of Engelbert to make his archiepiscopal cathedral into one of the most important in the Holy Roman Empire led him to urge the construction of an entirely new building, but the start of the work was delayed by his murder in 1225, and it was not until1248 that work began.
The original intention had been to demolish only the west transept of the existing building, so that the remainder could continue as an archiepiscopal church, but careless demolition led to the destruction of the entire building by fire, and so the way was clear for the creation of an entirely new building under the master-builder Gerhard. It would appear that he was familiar with the great French cathedrals, especially Amiens; however, it is unlikely that he had worked there, since he incorporated the artistic components of Amiens without the technical innovations that took place there. Gerhard died around 1260 and work continued under his assistant Arnold, who was in charge until 1299. work continued steadily at the chevet (east end), where the painted windows were installed around 1310; the cathedral Chapter was able to install itself there and consecrate the high altar in 1322, after 74 years of construction.
Meanwhile, work was under way on the western part of the cathedral, and continued under successive master-builders until1560, when all work ceased on the instructions of the Chapter, for reasons that have never been satisfactorily explained. By this time much of the nave and the four side-aisles (continuing the plan of the Romanesque building) had been completed, along with the main structure of the lofty south tower of the west end. Despite numerous efforts, the cathedral remained in an uncompleted state for the following centuries, although some additions were made to the furnishings and decoration. When the French seized Cologne in 1794 the Archbishop and Chapter moved to Aachen, and the building was used first for storage of grain and fodder and then as a parish church. However, interest rekindled and a movement for its completion got under way. work was to begin again after Cologne passed to Prussia in 1815. Karl Friedrich Schinkel visited the cathedral in 1816 and sent his talented pupil Ernst Friedrich Zwirner there as Cathedral Architect. Work did not begin, however, until 1840, financed jointly by the Prussian King Friedrich Wilhelm IV and an independent Society of Friends of the Cathedral (which raised enormous sums from a series of lotteries). By 1880 the building was complete, after 632 years and two months.
During World War II the cathedral suffered tremendous damage during air-raids: no fewer than fourteen heavy bombs reduced it to a pitiful state. Restoration and reconstruction work rendered the chevet usable in time for the centenary celebrations in 1948, but the remainder of the building was not restored fully until1956.