|Fig. 1.12, 1.13 "Sponsored" Art in the Renaissance [Source]
the period. To eat, they sold their work to those who could pay for it. And in producing it, they adapted their creative ideas to what their benefactors wanted. This didn't mean, of course, that all creativity and talent was subverted. Michelangelo included portraits of himself in many of his works, and artists often had ideas that were saved and worked into the pieces they were asked to do.
And what was all this art used for? In addition to being "for the glory of God" (or more cynically, to demonstrate wealth and power), the Church used religious art for instruction. Imagine pilgrims coming for the first time to a great cathedral. Unlike today, when even a cathedral may be dwarfed by modern office buildings or hidden behind elevated highways, the church would have stood as the largest building in sight — bold, incredible, and majestic. Inside, a priest might lead the worshipers to the stained glass windows. In a world where visual images were scarce (no TV, no magazines, no Internet), these images of the Nativity, the life of Jesus, the Crucifixion, the Resurrection, and the Saints had enormous power. They would give form to ideas. They would instruct and teach. They would hold sway over the minds of believers.