The Mosaic "The Last Judgement"

The Golden Gate - the southern entrance to the cathedral of St. Vitus - is decorated with a unique work of art, a coloured, richly gilded mosaic representing the Last Judgement.
Time and environmental influences over the centuries are destroying this wonderful memorial. The dilapidation of the mosaic is mainly caused by surface damp, the polluted atmosphere and mechanical damage. So in the spring of 1993 a monitoring station was set up on the cathedral, whose records show the influence of the environmental agression on the stability of the mosaic and make it possible to decide on the conditions necassary to evaluate the suitability of protective coating.
In summer 1998, after the thorough analysis started the work of restoration headed by the professionals from the Office of the President, Prague Castle Administration and the Getty Conservation Institute from Los Angeles (USA). The restoration, including cleaning, supplementing the missing cubes, putting on a protective coating and where necessary gilding, will be followed with a regular maintenance and monitoring of the mosaic.

History of the mosaic
At the time of Charles IV, Bohemian king and Roman emperor, Prague became a shining jewel of the Holy Roman Empire. The Emperor had built a magnificent cathedral in Prague Castle. On his journeys in Italy he had seen beautiful mosaics and he decided to decorate the Golden Gate of the cathedral with the same technique. The work was started in 1370 by unknown mosaicists, who completed it in a year later.
The mosaic is one of the most precious artistic memorials in the Czech Lands. It is the most important medieval example of this technique north of the Alps, a unique value of graphic art, of historic importance, in the extent of its technical execution. It is composed of almost a million glas cubes and little stones of more than thirty shades of colour.
The mosaic was several times cleaned and restored even during the 15th century, soon after its completion. But in the following centuries it became even more dilapidated, despite numerous attempts to save it. By the eighteen-eighties it was in really critical state. In 1890 a great storm damaged the mosaic so badly that it had to be entirely taken down from the Golden Gate. Stonemasons and mosaicists from Venice, working for two months, cut it up into 274 pieces, and these they brought on panels into the store-room beneath the Vladislav Hall, where they restored them. In 1910 the renewed mosaic was one more placed over the southern entrance to the cathedral.
Forty years later the surface of the mosaic again became corroded owing to the adverse effects of the surroundings. In 1953 Czech restorers and scientists prepared an extensive study, on the basis of which it was cleaned, restored, regilded and given several layers of polymer coating. But without regular maintenance by restorers not even this protective layer prevented the work from deteriorating further.
In 1992 the Office of the President of the Czech Republic and the Getty Conservation Institute began to cooperate to restore and conserve the mosaic.