Complex sentence: The legend was actually formalised by Sir Walter Scott and others who subsequently instigated a town festival called "The Cleikum Ceremonies" in 1901, and saw this as a way to stop the legends and folktales of the region from dying out.
Split into simpler sentences: The legend was actually formalised by Sir Walter Scott and was later instigated in a town festival called "The Cleikum Ceremonies" in 1901. This was seen as a way to prevent the legends and folktales of the region from dying out.