These are four "mini stand up posters" that were displayed in windows of movie theaters when The Sword in the Stone premiered in 1963. Beautiful compositions for this unusual format, as well as terrific character depictions and gorgeous color. This is some of the best advertisement art for any Disney movie. It is interesting to see Bill Peet's story credit here.
I believe the artist might have been Al White, who also illustrated a Golden Book featuring the film's story. Years ago I had the opportunity to see the original book illustration/paintings over at Disney Publishing. Let me tell you, they took my breath away. Absolutely stunning!