Check out the Medieval section to see the earliest surviving stained glass images, which date to the late 10th or early 11th century—just exactly when tiny windows started replacing the huge windows used before the craze for vaults.

Stained glass may have been used for image-making before this, but we have little good proof of it. But we do know that churches used patterned translucent stone to change the light inside, and that they also set coloured glass in the windows. Let's start with the use of patterned stone.

St Paul's without-the-walls, Rome, 4th century

Despite a catastophic fire, the church of St. Paul's without the walls in Rome looks much as it did when it was completed soon after Christianity was legalized. Its classically beautiful golden interior with geometric patterns and structures is justly famous. But we don't often get to see its windows, although here is a most unusual shot of them in situ. Look how big they are—taller than doors! And take a look at this one—made of patterned and matched slices of striated alabaster. No two are the same! The light comes through soft and gold, setting up an aura of mystery and reverence.

Haghia Sophia, Istanbul, 6th century

This church was the palace chapel for the Byzantine Emperor, and was the biggest church in Christendom until Wren built St Paul's in London, 1661. It still has the biggest dome, with a span of 120 feet. Now, take a look at its stupendously enormous interior. Every curved surface is mosaiced in real gold, and the walls and columns are sheathed in multicoloured and patterned marble. And in between, the capitals foam like white stone lace.

That dome is ringed with geometrically ideal windows, and the light streams in and blurs the structural forms, making it seem to float. But it wasn't always like that. We know that when it was built, the windows were filled with coloured glass—glowing greens, moody blues, and deep purple—whose sun-shifting colours were caught and reflected by the golden mosaics to create a sense of mysterious presence.

Whose presence? God's, of course! Think of it in Classical terms: perfect gigantic globes of space, 100 feet above your head, edged with gold and filled with moving colour! This photo of the apse may give some idea of the effect.

God is Light

These are the origins of stained glass. Filters to soften and colour the light so that we can almost see God manifest himself! So it comes as no surprise when, 400 years later, the next step is to show Christ Himself manifested in coloured glass. After all, there were many who hoped he really would come back in the year 1000 A.D.

So now—why not find out how Gothic architecture suggested the earth-shaking effect of God actually manifesting Himself, in The Vault as Illusion.