Complex sentence: Before the mid- 1400s illuminated books were considered a higher form of art than panel painting, and their ornate and luxurious qualities better conferred notions of wealth, status and taste on their owners.
Split into simpler sentences: Before the mid- 1400s, illuminated books were considered a higher form of art than panel painting. Their ornate and luxurious qualities better conferred notions of wealth, status and taste on their owners.