'York Minster Revealed’: Great East Window Conservation (2012-2018)

National Lottery Heritage Fund and York Minster Fund: University of York,York Minster and the York Glaziers Trust

Collaboration: the University of York, York Minster, the York Glaziers Trust

Funding: Part of a £10,543,000 project at York Minster - The National Lottery Heritage Fund; York Minster Fund; individual donors

Duration: 2012-2018

Principal Investigator: Sarah Brown (University of York and Director, the York Glaziers Trust) 


York Minster Revealed was a major research and conservation project at York Minster that ran from 2012 to 2018 and included a £10.5 million grant from the National Lottery Heritage Fund.  Central to the project was conserving and reinstating the 600-year-old Great East Window, the largest single expanse of medieval stained glass in Britain.  The project involved close collaboration between glass and stone specialists.

Members of the Department of History of Art at the University of York worked with York Minster and the York Glaziers Trust on the restoration and conservation of the Minster’s Great East Window.  Both prior to and throughout the project, input from the the multi-disciplinary East Window Advisory Group (EWAG) was key to steering the project.  Established in 2005 to develop and support the work of the conservators, EWAG members included University of York art historians Sarah Brown (also Director, the York Glaziers Trust), Professor Tim Ayers, Professor Richard Marks and Professor Christopher NortonDr Ivo Rauch, an independent conservation specialist; and representatives of the York Chapter and the York Minster Fund: the Reverend Canon Peter Moger, Precentor; Andrew Arrol, Surveyor of the Fabric for York Minster; and Dr Richard Shephard, Director of Development.

The grant also funded glazier and stone mason apprenticeships at the Minster.

Sarah Brown oversaw the work on the window, which involved a team of colleagues from both the University and the York Glaziers' Trust, including  Professor Ayers and Professor Norton. She also provided unprecedented hands-on experience to students on the University’s taught MA in Stained Glass Conservation and Heritage Management, for which she is Course Director.

Univerisity of York, MA students (Stained Glass Conservation and Heritage Management)on the scaffolding of the Great East Window, York Minster,

University of York MA students (Stained Glass Conservation and Heritage Management) on the scaffolding of the Great East Window, as part of a seminar on protective glazing conducted in the Minster by YGT conservation manager Nick Teed

This is the first time that a project of this scale has been attempted with researchers working alongside conservators: so, the partnership […] between the University and the workshop has been a new benchmark for taking projects of this kind forward.

- Sarah Brown

The Great East Window

The window is the masterpiece of Coventry glazier John Thornton and was commissioned in 1405.  it took three years to complete, according to information gleaned from 17th-century copies of the medieval contract, which has long been lost.  The window was a work of immense ambition, depicting the beginning and end of all things, from the creation of the world as described in the book of Genesis, to the events that will presage the end of the world and the second coming of Christ as told in the visionary Book of Revelation, known in the Middle Ages as the Apocalypse.

Read more about the history of the window and past restoration work on the York Glaziers Trust website.

The Project

During the first phase of the project (2012-2016), the 157 panels narrating the Apocalypse were removed and painstakingly conserved at the York Glazier’s Trust Studios.  In the second phase (2016-2018), the conservation of the remaining 154 panels was carried out.   The panels were returned to the Minster following parallel work on the masonry at the East End, which involved the conserving or replacing of nearly 2,500 stones.

Previous protective glazing had acted as a weather shield, keeping pigments, lead, conservation materials and the original glass dry; however, it had not been an adequate barrier to ultraviolet radiation, which reacts with any epoxy resin used in the conservation of the stained glass, leading to a yellowing discolouration of that resin after prolonged exposure.  For the York Minster Revealed project, a layer of new, state-of-the-art restauro®UV glass was added, so that each panel is now protected by this revolutionary external glazing incorporating UV-resistance within the structure of the glass itself.  This was the first time this glass had been used in the UK and it is intended that, eventually, it will be used to protect all the original medieval glass at York Minster.

“It is reassuring to know that we are now able to offer total environmental protection for all aspects of the conserved window.”

- Sarah Brown

The scenes and narratives depicted in the panels were studied and the panels were reordered in line with what research revealed to be their original positioning.  Through a combination of art historical research and forensic examination of the glass itself, attempts were also made to recover the original outline of the panels.  Later additions of lead were removed during the conservation process, revealing original details and with the additional fortuitous effect of allowing more daylight through into the Minster.

York Minster Revealed - before & after conservation, panel 5b

Panel 5b (Revelation 13:4-6): left to right, before and after conservation. Photos: the York Glaziers Trust, courtesy Dean and Chapter of York

Enhancing the Visitor Experience

Whilst the East End of the Minster was concealed by scaffolding and sheeting for the duration of the project, the public as well as academics and students from the University of York were given almost unprecedented close-up access to both the conservation process and the stained glass.

Visitors were able to watch York Glazier Trust’s conservateurs at work in their studio, set up as a visitor centre with Heritage Lottery funding in the disused medieval St Bedern's chapel in Goodramgate.

In the Minster itself, in order to maintain access to the stained glass of the East Window during the restoration, five panels were displayed in the specially constructed Orb from 27 October 2012 to 31 May 2016. Four panels remained on permanent display throughout this time, whilst the fifth was changed to a newly conserved panel on a monthly basis: in total some 35 panels of the 311 that make up the Great East Window were displayed, allowing visitors to encounter the details within each scene at close quarters for the first time.  

The Orb, a 10m wide, 3m high metallic pod, was designed by Mather & Co. and produced by Paragon Creative. It was very well received by both the press and visitors, including: ITV; Design WeekYork Press; The Daily Norm ('York's Stained Glass Sensation'); Yorkshire LifeVidimus; Yorkshire LifeBBC, Zombie Parent's Guide; Art Docent Program; Intravenous. More than 1.4 million visitors to York Minster had the opportunity to encounter the panels at close quarters in the Orb, and this enhancement of the visitor experience has been attributed in part to the increase in visitors, as opposed to the decrease that might otherwise have been expected, considering the East end was covered in scaffolding throughout the project (for example, see York Press).

The Orb, York Minster - Photo: ©University of York/John Houlihan

The Orb, York Minster. Photo: ©University of York/John Houlihan



  • 15 November 2018 - Research Seminar - 'Looking for John Thornton: The Great East Window of York Minster Revisited' - Sarah Brown at the University of York
  • 10 November 2018 - 10th Anniversary Masterclass - 'A Decade of Discovery: The Great East Window of York Minster' - King's Manor, University of York
  • 31 May 2018 - Author Talk – 'The Rediscovery of a Medieval Masterpiece: John Thornton’s Great East Window' - Sarah Brown at York Explore-  Library and Archive
  • 17 May 2018 - Celebratory Evensong at York Minster and re-dedication of the Great East Window by the Dean of York, the Very Reverend Vivienne Faull, followed by a reception
  • 12 May 2018 - Diocese of York pilgrimage to York Minster, culminating in an evensong service of thanksgiving for the completion of the work on the Great East Window: 'Twentieth-century choral music from Eastern Europe to celebrate the unveiling of the Great East Window at York Minster'
  • 10 March 2018 - Concert - 'Voices from the East' - Chapter House Choir, directed by Benjamin Morris, in the Chapter House, York Minster
  • 10 February 2018 - Concert - 'Stories in Glass' - Yorkshire Bach Choir at St Michael le Belfrey, York; in collaboration with the National Centre for Early Music, York - a programme of music 'music inspired by stained glass and the wider history of York'
  • 24 July 2013 - Annual lecture, The Stained Glass Museum, Ely - 'John Thornton' Stained Glass Apocalypse (1405-8): The Creation and Conservation of a Medieval Masterpiece' - invited speaker, Sarah Brown, at the Art Workers' Guild, London


Throughout the project, different milestones and its culmination with the unveiling of the newly conserved Great East Window were reported widely, including confirmation of a remnant of medieval lead, probably part of the original creation of the window (Vidimus, Issue 79).  Sarah Brown reported on 'York Minster’s Great East Window: The Last Panel Returns' (Vidimus, Issue 117); and news items were published by, among others: The Simthsonian's Smartnews; York Press (February 2012, April 2015, July 2017 (the 50th anniversary of the York Glaziers Trust); November 2017; and the Telegraph; BBC; The History BlogIcon (The Institute  of Conservation) - interview with Sarah Brown; ICN (Independent catholic News). Photographer Duncan Lomax documented the different stages of the process, summing up the project in this post.

'One of the objectives of our project was really to put this work of art on the map because it is one of the most extraordinary and ambitious pieces of stained glass ever conceived and executed.'

– Sarah Brown

'York Minster Revealed has had a huge, positive impact.  To see the East End in a new way, in ways that none of our predecessors have, has been an absolute delight. Alongside that, we have turned ourselves more to face the outside world. So through our project work with schools, with families, with young offenders, with artists, with faith communities across the region, we have discovered and forged new relationships: and it’s those new relationships that will help us to continue to develop York Minster for the future.'

– The Very Reverend Vivienne Faull, Dean of York


2018 - York Design Award, Conservation/restoration category - 'New techniques [...] have been combined with extensive research into the original glazing techniques and the interpretation of the window’s complex narrative'

2018 Design York Awards - Great East Window, York Minster; l-r Andrew Scott, Nick Teed, Sarah Brown, Trevor Lawson

York Design Awards 2018, Shannon Award for conservation/ restoration, joint winner: Great East Window, York Minster. Andrew Scott of York Civic Trust (left) presents the award to members of the Great East Window team at the York Glaziers Trust, Nick Teed, Sarah Brown and Trevor Lawson. Photo: Duncan Lomax, Ravage Productions

2014: York Design Award for the Orb, in the Landscape/Open Space/The Public Realm category

Further Reading

'Preserving York Minster's Great East Window': the project, led by Sarah Brown, featured in the University of York's 50th Anniversary 'Changing the World for 50 Years' series.

York Glazier Trust's case study of the York Minster Revealed project.

The National Lottery Heritage Fund's announcement of the project's completion.

Historic England's report of the project.

[Published August 2019]

Main image: The Great East Window, York Minster. Detail of a photograph by 'Derwisz', reproduced under CC licence BY-NC-SA 2.0, flickr.com/photos/derwisz/39323863910

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