Much of the glass in the Great East Window, including the nineteen figures, is medieval.
Nine of the figures date from 1304. Three of them are located at the top of the window. They still have their original faces and, from the lettering on their scrolls, are identified as Abraham, Moses and Isaiah. The six outer figures of the bottom row are also from 1304, but the faces of these saints are not original.
By 1390, the stonework of the original window had become unsafe. A new window was constructed in the perpendicular style and the tracery of this window remains today. Original glass was included with new glass when the new window was glazed in 1391.
A grant from the First World War Centenary Cathedral Repairs Fund helped to pay for the glass to be inspected, recorded and repaired. Isothermic glazing has been added, which will protect the glass behind.