I've learnt not to ask about the stained glass when visiting churches as the information I want (who made it? when?) is rarely there. I am usually told that it's only Victorian and then given stories about the iconography. However in the oldest building in Cheltenham, St Mary's Church, there are two guide books which in combination tell you almost everything you need to know. One takes you around the church with pictures, plans and bible references, while the other (not to be taken away) gives you historical information.
The beauty of The Rose Window (above left) is in the fourteenth century tracery, slightly angled and very low in the wall - east facing in the north transept. All of the windows on this level are filled with stained glass from the late nineteenth century. Here are photographs of some of my favourite details: the H,B&B radiating star (above right), The Parable of the Talents (below left), foliage done in a completely different way by Clayton & Bell in the window of St. Peter (below right) where I also love the painted ship and the pale landscape colours.
I'm not able to guess which firm made the North Transept window (information missing from the book) whose apostles showed up well in the afternoon sunlight (below). The L,B&W Last Supper Window also looks particularly good in the fine ancient tracery and is full of the sort of details that people love to point out. This from the guide book: 'Can you see the disciple with the brown halo in the far right panel? This is probably Judas Iscariot..."