Talk about being under-rated.

I ask you, friends, who was it who anticipated all the squares we find in art today, all the tiling, all the gridding? Was it much vaunted Ur-creator Picasso? No. Was it hipster Warhol? No. Was it even my hero that I discovered reluctantly, Jennifer Bartlett? No. Was it Sol LeWitt? Please. Matisse? Close. I'd say it was Pierre Bonnard.

Look at Bonnard and you find the little squares all over the place. Not only in the tiles of the now famous bathroom, but in the French table clothes, even in the trees. Bonnard is the man.

Before that you have to look at medieval manuscripts for anything similarly modern.