Jigsaw puzzles were invented in 1760 as a tool to teach geography. Dick Sawbridge with that stripy blanket on his lap used to make puzzles for the British Jigsaw Library and the Royal Family. He once made a puzzle for the Queen that featured a collage of corgis. He would use very clever cut designs to make the most challenging of puzzles - none of this die-cut cardboard business. I found all of this out in a great Cabinet article that you can find here.