King Cnut the Great: ruler of Denmark, Norway, Sweden and England, despite his successes, his legacy (in the UK at least) was pretty much obscured by the Norman invasion of 1066 and the death of his son, King Harold. Nowadays he’s best known for his role in folklore.
The story goes that he put his throne on the beach and commanded the tide not to come in. Obviously he ended up getting his feet wet, and the tale gets interpreted in one of two ways – either the futility of arrogance or as a king going out of his way to show that you shouldn’t claim power that only belongs to God.
A thousand years later, North Carolina has proposed a law that would prevent the sea level from rising (or, at least, measuring it in an inconvenient way).
I can’t think why I’ve linked the two…