Video: Great East Window restored to York Minster

The first panels of a revolutionary glazing have been put in place to provide state-of-the-art protection for the country’s largest medieval stained-glass window.

Renowned craftsman John Thornton’s masterpiece, the size of a tennis court, was removed from its home in the spring of 2008. Until now, work has focused on preserving the stone which surrounds the Great East Window.

But this week marked a major milestone for the restoration project, as York Minster became the first building in the UK to use the UV-resistant glass manufactured by the world-famous Glasshutte Lamberts in Germany.

“This is a first for York and the country and a really important step forward,” said Sarah Brown, director of York Glazier’s Trust.

Any visitors expecting to see the dramatic depiction of the story of the Apocalypse in place in its full glory soon, however, face disappointment.

So intricate is the delicate task that it will take a team of 11 stained-glass experts just under two years to complete more than 300 individual panels.

“We have a way to go yet, but we’re on the home stretch,” said Ms Brown.

“We’ve had to take each panel out, and in turn each panel has thousands of individual small glass fragments.

“When we took them out the panels were dirty, some were very badly broken and fragmented. So we’re trying to repair some from some older attempts at restoration.

“One the one hand we’ve got this real state-of-the-art material which will support the panels and create a sort of mirror image. On the other hand, many of the crafts and skills used are familiar to those which would have been used by the medieval glaziers.”

For more than 600 years, the creation and piecing together of those finely-detailed panels has been something of a mystery.

While many aspects of the work go unrecorded, getting up close with the panels each day has allowed the team to build a clearer idea of the method behind the masterpiece.

“Even though the team has been working on this for four years now we’re constantly noticing new things,” said Ms Brown. “We know a certain amount about the history of it, but we’re understanding more about how John Thornton’s workshop was organised.”

Some of the most fascinating aspects are the Bible extracts, written in Latin with such accuracy that today’s experts have concluded Mr Thornton had a specialist scribe in his small team.

The conservation of the Great East Window is part of the £10.5m York Minster Revealed project, funded by the Heritage Lottery Fund.

Work is due for completion in March 2016, and in the meantime visitors can see glass panels from the window on display in The Orb exhibition space, which is in York Minster’s East End.