The primary characteristics of early English glass are deep rich colours, particularly deep blues and ruby reds, often with a streaky and uneven colour, which adds to their appeal; their mosaic quality, being composed of an assembly of small pieces; the importance of the iron work, which becomes part of the design; and the simple and bold style of the painting of faces and details.

In early windows, before the introduction of stone tracery, the leaded panels of glass were inserted into an iron lattice or framework of upright and horizontal bars forming squares.

In the lower windows, closer to the eye, each square space was filled with a single subject or image, usually framed by a circle.

They took advantage of the delicate patterns of the tracery in the windows, added decorative illustrations in the margins, and often placed the central figures beneath elaborate arches and canopies.

The best-preserved is the east window in the part of the chapel called "Becket's Crown", in which only four or five of the twenty-four medallions are later copies.

During English Civil War in 1642–43, Puritan iconoclasts attacked the windows throughout the cathedral, climbing ladders and swinging pikes to smash the glass, which they considered to be idolatrous.

[2] Another collection of early windows is found in the Jerusalem Chamber of Westminster Abbey, built by Henry III of England, the brother-in-law of Louis IX of France, the creator of Sainte-Chapelle.

It was brought about in part by changes in the architecture of English cathedrals and churches, and also by technical innovations, such as the use of silver stain to colour the glass.

This meant that windows could no longer be composed entirely of a mosaic of small circular medallions of deep, rich colours, as in the 12th and 13th centuries.

The most elaborate decoration was not in the painted glass, but in the tracery, in the stone mullions and iron bars that formed the framework for the window.

Oxford Cathedral and the Abbey Church of Tewkesbury in Gloucestershire contain early white windows painted with silver stain.

The Dean's Eye was begun by the French-born Bishop, Saint Hugh of Lincoln, in the Early Gothic period in 1192, and was completed in 1235.

The use of pale backgrounds continued, particularly panels of white delicately decorated with flowers, animals and coats of arms, which surrounded and set off the more colourful main figures.

[11] Improvements in the techniques of painting on the glass in vitreous enamel accelerated the tendency toward realism and a painterly[clarification needed] style.

Additional colour was brought in by adding touches of gold (made with silver stain) to the painted architectural canopies, pinnacles and crockets around and above the figures.

The faces in Late Gothic were more finely drawn than in earlier styles, a development influenced by Flemish painting.

English glass craftsmen established important workshops in York, Norwich, and Oxford, which served clients in the surrounding regions.

These clients included not only cathedrals and nobles, but also wealthy merchants and landowners who wanted impressive windows for their new residences.

Another example was John Prudde, the King's glazier, who made the glass for Beauchamp Chapel of Saint Mary's at Warwick, which was commissioned in 1447.

Several important English works, such as windows at Fairfield Church in Gloucestershire and at King's College Chapel, Cambridge, were probably by Flemish artists, such as Dirk Vallet.

Some of the last windows, such as those by Abraham Van Linge at Christ Church Cathedral, Oxford, were simply like large paintings viewed through a grid of lead lines.

The first important group of Renaissance windows in England was commissioned between 1516 and 1526 and installed at King's College Chapel, Cambridge.