Dumb atheist warning:
Great pictures but narrator states that Christians were worshiping the light of the sun through the windows (just like many pre-Christian religions) of the Cathedral. Stupid leftists at every turn.
The symbolic connection between the light of the sun and god's light is deliberate and intentional. Christianity has never minimized this or been the least bit embarassed by it. Indeed, why do you think the church spent so much on windows in the first place?
Not everything in the world is a left-wing plot, even if it seems we are getting awfully close these days.