American Glass Guild





The Restoration & Conservation of the Dean’s Eye Rose Window

The Dean’s Eye rose window, in the North Transept of Lincoln Cathedral, England, is one of the most important examples of medieval stained glass in Great Britain.  It was begun in 1220 and completed in 1235.   The original flat tracery window with its 77 panels tells the story of the Last Judgement.

In Christian art the painted glass of the Deans Eye played a fundamental role for the Catholic Church in teaching the medieval worshiper and pilgrim the story of the Second Coming of Christ to judge the world.  The historic glass is composed of an arrangement of sixteen outer panels representing the Last Judgement, which originally also contained images of Hell and Damnation, and sixteen inner panels representing the Kingdom and the Blessed of Heaven.   Christ in Majesty is the central focal point in the middle of the tracery.

Historically the Deans Eyes glass and its masonry have received much attention from overzealous 16th Century iconoclasts, 17th Century neglect, 18th Century re-arrangements, 19th Century archaeologists, early 20th Century restorers, and more recently 21st Century structural engineers.   This has not always been beneficial to the window.

Over the last two decades the main focus has shifted from considering only the important collection of medieval glass to also analyzing the structural capability of the historic tracery and making the decision to restore the window in its entirety, rather than just concentrating on the glazing. 

Between 1989 and 2005 the window has been the subject of a major restoration programme at a cost of over £2 million.  The essential restoration work was not only a straightforward conservation of the historic glass, but also involved the replacement of the medieval stone tracery, the conservation of the 13th century wrought iron ferramenta and a search for an acceptable solution for the long term protection and preservation of the ancient glass.

For the glaziers dealing with the conservation of the medieval glass, the work followed the standard principals and techniques of any ethical stained glass conservation.  The real challenges however, lay in overcoming the practical issues of restoring a built architectural artefact, considering the structural engineering and the dismantling and re-building of the window.   Restoring a window of such complexity and historical significance can only be achieved by allowing a highly motivated and skilled conservation team to do their job.  A project of such calibre needs to be carefully discussed, planned, organised and of course financed. 

The Deans Eye Rose was completed in November 2005 and the window was graciously handed over to the public in May 2006 by the Prince of Wales, who called it a celebration of completion and a great achievement.  


Personal Information


Born in 1963, I was raised and educated in Bad Neuenahr-Ahrweiler, one of the most beautiful wine growing regions in Germany.  I spent most of my early adult life travelling around Great Britain.  In my mid 20s and living on the northwest coast of England, I attended a summer course in stained glass and soon found myself busy making leaded lights and coloured glass windows for the domestic market.  Being strongly interested in restoration and conservation I took the opportunity to work for various parish churches in the area restoring mainly 19th and 20th Century ecclesiastical stained glass windows.  After selling my stained glass business in the Lake District I moved for a brief spell to Germany where I worked for a large commercial glazing firm in Bonn. 

In 1993 I retuned to Britain and began working for the Dean and Chapter of Lincoln Cathedral.  Being on the bench for a number of years I embarked on some further educational development and in 2001 gained my Post-Graduate Diploma from DeMontfort University in the Conservation of Historic Objects.  Two years later I completed my MA in the same studies, writing my dissertation on the effects of manganese browning on medieval glass.  Since 1999 I have been the Team Leader of the Lincoln Cathedral Glazing Department, supervising and completing a variety of major conservation projects on windows dating from the 13th to the 19th Centuries.   


Mr. H. Thomas Küpper

Lincoln Cathedral

Works Department

28 Eastgate

Lincoln LN2 4AA

Great Britain


Tel.      01522 561620

Fax.     01522  561619










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Last modified: 6/24/08
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